In the Name of Allah, the most Compassionate, the most Merciful
And bless be upon Muhammad and his pure Household, and may Allah's curse be on his enemies from now until the Day of Resurrection! And there is no power or strength except for the Lofty Glorious Allah.
The Wise Allah has stated in His Glorious Book:
وَيَقُولُ الَّذِينَ كَفَرُوا لَسْتَ مُرْسَلا قُلْ كَفَى بِاللَّهِ شَهِيدًا بَيْنِي وَبَيْنَكُمْ وَمَنْ عِنْدَهُ عِلْمُ الْكِتَابِ 
‘… yet those who disbelieve, say, ‘You are not a Messenger.’ Say, ‘Allah is sufficient as a Witness between you and I, and so is one who has the knowledge of the Book, (Qur’an: 13/43).’
The opinions of all the scholars of Shiite are that the part ‘who has the knowledge of the Book’ in this noble verse, is the Commander of the believers, Upon Him be Peace, and the Messenger of Allah, Bless be to Him and his Descendants, who, with the permission of Allah, tells the believers who denies to accept the Qur’an and the messenger-hood of that Holiness: ‘The best of you with enough witness between you and I to confirm my claim and the truthfulness of the Qur’an is the Holy Essence of the Creator and the Commander of the believers, Upon Him be Peace, who has the most knowledge of the Qur’an, and is acquaintance with the facts and the secrets; and so is he aware of every minute occurrence , the fine, manifest and hidden in the Qur’an.’
And all the narratives witch have been related by the Household, Upon Them be Peace, without slightest difference have unanimously agreed the revelation of the verse to be in his honour.
And a great number of the Sunnite’s scholars believe that it means the Commander of the believers, though some of them have said: ‘The purpose of, ‘who has the knowledge of the Book’ is Allah, the Glorious, Himself or Gabriel or the scholars of the Jews and Christians who are the most learned of the Bible and Torah – or most probably he is Abdullah bin Salam who has embraced Islam.’
Abu al-Fotoh Razi says: ‘Some of the commentators have said, ‘He is Abdullah bin Salam, and most of the ancient commentators, narrators, and those who follow the news and documents – whether they are agreeable or against – believe that he is the Holiness Commander of the believers.
Zamakh’shati says: ‘It means one who owns the whole knowledge of the Qur’an; the same Qur’an that with its strange combination and miracles has afflicted man to prepare a thing similar to it. And then, by this phrase «و قيل» it has explained many other probabilities and statements. 
And it is better for us, before referring to the narratives that have been related by the Sunnite and Shiite about this verse, and also before explaining the opinions and the statements concerning this verse, it is necessary to have a brief look at this blessed verse (The Thunder) until the condition of the verse to become clear. Above all, this brief investigation will be a good answer to the ‘probabilities and the some statements concerning the this verse.
The revelation of this chapter is for affirming the truthfulness of the Divine Book, the Glorious Qur’an; though the disbelievers did not accept the Qur’an as a miracle and they kept asking the Messenger of Allah, Bless be to Him and his Descendants, for another clear and obvious miracle to be sent down for them from the heavens. The verses of this chapter, from the very beginning to the end, are related to each other; they are like transparent pieces of pearls set together and made a beautiful outline. Its beginning is related to the last one and so is its final part to the first one.
The verse that is our concern, is at the end of the chapter, and it is a good answer to all disbelievers. It is in such a way that if this verse is taken away the whole chapter is deformed and it looks like as a broken bowl – it looses its magnitude and dignity.
The chapter begins with this verse:
المر تِلْكَ آيَاتُ الْكِتَابِ وَالَّذِيَ أُنزِلَ إِلَيْكَ مِن رَّبِّكَ الْحَقُّ وَلَكِنَّ أَكْثَرَ النَّاسِ لاَ يُؤْمِنُونَ
A, L, M, R, (ălïf, lām, mïm, rā). These are the Signs of the Book; and what has been revealed to you from your Lord is the truth, even though most people do not believe, (Qur’an: 13/1).’
Then, it goes on introducing Allah that: it is He Who has set up the heavens without any visible columns, and He has settled Himself in the Being Mansion, has the sun and moon under His control and made them move. He has spread out the earth and set the chains of mountains on it. He has made the rivers and spring flow and has different kinds of fruits to grow. He has divided the earth in different divisions and qualities and has created gardens for grapes, dates and different agricultural allotments which all are irrigated with the same water – He enlivens the dead. And it is very surprising that the disbelievers say:
‘After we are dead and gone, shall we re-appear in new clothing?’ It goes on up to the seventh verse which says:
وَيَقُولُ الَّذِينَ كَفَرُواْ لَوْلآ أُنزِلَ عَلَيْهِ آيَةٌ مِّن رَّبِّهِ إِنَّمَا أَنتَ مُنذِرٌ وَلِكُلِّ قَوْمٍ هَادٍ
‘… and the disbelievers say, ‘Why is not a miracle revealed to Muhammad, Bless be to Him and his Descendants, from his Lord?’ [O, Prophet], you are just a Warner; and for every nation is a guide, (Qur’an: 13/7).’
Here, it is clearly seen that the disbelievers did not accept the Glorious Qur’an which is a patent miracle and has been sent down as the Truth, but instead, they were after odd and strange miracles. That is why, to their demands, the Messenger says that:
‘Bringing other odd and strange miracles that you desire for (and, through your passions, you try to compel me to do it, such as: changing the mountain to gold, making the melted gold run in the streams, changing a certain garden into a garden full of jewels and pearls. And many more things such as restoring the dead to life, or bringing visible angels down from the sky, and bringing the whole tangible Qur’an down for you, and many more that most of them are ridiculous and totally wrong, they require the substance of Allah and His location in a certain place. Therefore, these kinds of miracles are always against the good intention of man. Although many messengers would present verities of miracles but they had not taken them as the bases for their affairs. That is, they were not there to shut down their main commission and surrendering themselves to the nation and always bringing miracles for them.)
I have come to warn you against disbelief and ugly affairs, this is my main duty, messenger-hood and the commission.’
Here, the Messenger should state: ‘The undeniable, scientific and everlasting miracle of mine is this Qur’an with me which logically invites people to wisdom and knowledge and it emphasizes it. Then, He provokes the Jinn and man to come together and dispute on the Qur’an, and invites them to bring a chapter, or if they can, ten chapters like the Qur’an. Apart from that, the verses on their own, with such strange manners, and rightful logic which include the facts, wit and wisdom, the natural laws and rules which are for the benefit of the humanity. With such loud voice for the justice and piety, the benevolent deeds, invitation for the generosity giving away and some others all like the loops of a chain, connecting to one another and as the absolute miracle inviting people to the righteousness.
My Allah has sent down these verses, and within theses verses that Allah has introduced me as the Messenger are good witnesses – therefore, they have logically announced everything and are the best miracles.’
However, the Messenger does not answer them like this, he keeps it for the next time, but he goes on saying: ‘Allah is aware of every single (female) article gets pregnant, He is the Knower of the secrets and manifest, He has the knowledge of slow or loud speaking. He has created the lightening and the rain bearing clouds in the sky – the lightening is at the praising position, and the angels fear him and are always mentioning Him and saying His hymns.
Then, he states, ‘The invitation of Allah is right and those who accept this invitation are prosperous. And whatever in the heavens and on the earth exists prostrate Him, and the disbelievers who associate one as His partner are wrong. He continues similarly until he comes to the verse 19th:
أَفَمَن يَعْلَمُ أَنَّمَا أُنزِلَ إِلَيْكَ مِن رَبِّكَ الْحَقُّ كَمَنْ هُوَ أَعْمَى إِنَّمَا يَتَذَكَّرُ أُوْلُواْ الأَلْبَابِ
‘… What! Is one who knows what has been revealed to you from your Lord is the Truth, like someone who is blind? Only the sensible bear it in mind, (Qur’an: 13/19).’
Although this verse rejects the opinions of the disbelievers, it is related to the first verse and has been brought for the emphasis and the righteousness of the Book. And all the verses that the greatness and power of Allah are explained within are the explanatory of the Qur’an itself confirming the righteousness and calling the deniers blind. And then, it explains the wise people who accepted the Qur’an. It says: ‘They are those who keep their covenant with Allah, do not break their promise, and whenever Allah enjoins meeting the [the needy] relatives, they do so, they fear of Allah, they are afraid of their evil deeds, they perform prayers, they give away from their own property in secret and openly.’ He goes on thus until comes to the verse 27th.
وَيَقُولُ الَّذِينَ كَفَرُواْ لَوْلاَ أُنزِلَ عَلَيْهِ آيَةٌ مِّن رَّبِّهِ قُلْ إِنَّ اللّهَ يُضِلُّ مَن يَشَاءُ وَيَهْدِي إِلَيْهِ مَنْ أَنَابَ
‘… and those who disbelieve say, ‘Why does not a sign revealed to him from his Lord!’ Say, ‘Allah lets anyone He desires go astray, and guides towards Him anyone who feels concerned, (Qur’an: 13/27).’
Here, for the second time, he explains the objections of the disbelievers that why there has not been revealed an odd and strange miracle to him; and by this way, he makes us understand that the disbelievers are steady on their demand and do not take the Qur’an as the miracle and are looking for another miracle.
This tine, too, to their question, does not bring to an end his answer by referring the Qur’an to be the best miracle and he postpones this subject and Allah’s witness to his messenger-hood for some time later. He just says that: ‘Guidance and a wandering off are with Allah. One who believes in Allah and turns to him, and removes the veils of ignorance from upon his heart then Allah guides him. However, if one is not so, he walks in the stray path Allah will mislead him on that path.
And again, he continues explaining the attributes of the people who refer to Allah and walk in the straight path. They are those whose hearts tranquil by mentioning Allah; however, those who turn away from Allah, neither will miracles benefit them. When the people’s hearts are not in the state of the agreement and submission in front of the Truth, they translate all the miracles in a way that they mean witchcraft, magic and lies. Thus He states in the verse 31st:
وَلَوْ أَنَّ قُرْآنًا سُيِّرَتْ بِهِ الْجِبَالُ أَوْ قُطِّعَتْ بِهِ الأَرْضُ أَوْ كُلِّمَ بِهِ الْمَوْتَى بَل لِّلّهِ الأَمْرُ جَمِيعًا أَفَلَمْ يَيْأَسِ الَّذِينَ آمَنُواْ أَن لَّوْ يَشَاءُ اللّهُ لَهَدَى النَّاسَ جَمِيعًا وَلاَ يَزَالُ الَّذِينَ كَفَرُواْ تُصِيبُهُم بِمَا صَنَعُواْ قَارِعَةٌ أَوْ تَحُلُّ قَرِيبًا مِّن دَارِهِمْ حَتَّى يَأْتِيَ وَعْدُ اللّهِ إِنَّ اللّهَ لاَ يُخْلِفُ الْمِيعَادَ.
And if there were a Qur'an by which mountains would move along, or the earth would crack open, or the dead would speak out [they would still not believe]; but to Allah belongs the Power of command– about all things and affairs. Have those who have believed not become despaired [of their belief], and [have they not know that] had Allah willed, He could have guided all men? Disaster will continually afflict those who disbelieve because of what they produce, or it will settle down close to their home until the permission of Allah comes true. Surely Allah does not break the appointment [of His].
In these verses, He clearly explains that the reason for not agreeing the Qur’an is the heart’s not stooping to agree the Truth and submitting to the facts. And if they do not believe in this greatest miracle, the Qur’an, then which miracle are they going to believe? Then, it states the previous nations who, for their stubbornness and rebellion did not believe in their messengers; and also it states of the believers who, because of accepting the Truth will enter paradise. And then, the messengers who came for the guidance of men with their own miracles but the nations stood up against them with trick and deceit. It goes on until reaches to the final verse of the chapter:
وَيَقُولُ الَّذِينَ كَفَرُواْ لَسْتَ مُرْسَلًا قُلْ كَفَى بِاللّهِ شَهِيدًا بَيْنِي وَبَيْنَكُمْ وَمَنْ عِندَهُ عِلْمُ الْكِتَابِ.
‘… yet those who disbelieve, say, ‘You are not a Messenger;’ Say, ‘Allah is sufficient as a Witness between you and I, and so is one who has the knowledge of the Book, (Qur’an: 13/43).’
Here, it becomes quite clear that when the disbelievers did not accept the greatest miracle, the Qur’an, nor did the Messenger bring them the miracles they were demanding for, they totally rejected the messenger-hood. In the beginning, they were not denying it and they were expecting for another miracle, but later on, when they became hopeless of having another miracle, they absolutely rejected him. And in those two occasions that the Messenger had avoided to answer them about the truthfulness and the miracle of the Qur’an – but he referred to his own prophetic mission – has stated it here:
‘O disbelievers! This Qur’an, which is the greatest miracle, has been sent down to me, and in this Qur’an, my Allah bears witness at my prophetic mission. And he who is most learned on the Qur’an is a witness at my Prophet-hood.
The quality of Allah’s witnessing the Epistle of the most Generous Messenger, Bless be to him and his Descendants
According to Allah’s witnessing it turning to the secrets and unknown is impossible, it is claiming a thing without presenting a proof; as the testimony of Allah in the Qur’an and His Knowledge on His Book is clear to the disbelievers; but only claiming the righteousness of the miracles of the Qur’an is needed. Therefore, this noble verse that supervises the whole chapter is a good answer to the disbelievers and the pagans; and it dominates the first verse of the chapter and the 19th verse which confirms the righteousness of the Book. It also connects the very beginning to the centre and from that point to the fine ending; it has been connected in a way that if this verse is taken away from the chapter it easily comes to the sight that something is missing.
Now that our brief explanation on this verse has come to an end, we would better start commenting the verse:
قُلْ كَفَى بِاللّهِ شَهِيدًا بَيْنِي وَبَيْنَكُمْ وَمَنْ عِندَهُ عِلْمُ الْكِتَابِ.
Say, ‘Allah is sufficient as a Witness between you and I, and so is one who has the knowledge of the Book.
Here, Allah’s witnessing the Prophet-hood of His Messenger is stating it, as He states:
إِنَّكَ لَمِنَ الْمُرْسَلِين عَلَى صِرَاطٍ مُّسْتَقِيمٍ.
‘You are surely of the Messengers – on a Straight Path.’
And also other verses as:
يا ايها الرسول و يا ايها النبى،
Or stating to him with different titles, such as
محمد رسول الله، هو الذى ارسل رسوله بالهدى و دين الحق، و اطيعوا الله و رسوله، و لله العزة و لرسوله و للمؤمنين، و ما محمد الا رسول، و الله يعلم انك لرسوله، يا ايها الذين آمنوا اتقوا الله و آمنوا برسوله.
And the Qur’an is full of similar titles; and Allah bears witness by these in the Qur’an.
Fakhr Razi says: ‘The meaning of the witness is that Allah, the Exalted, has manifested the miracles by the hand of His Messenger that is accordance with his claims – this degree of witness is action not only verbal, and it is the highest degree of witness.  However, this word is not correct for the Messenger did not fulfill the odd and strange miracles that the disbelievers wanted, thus, only the Qur’an remains. So, in this case, there is no need considering the revelation of the Qur’an as Allah’s Own testimony, because the testimony, with its real meaning is aural witnessing that has been put in the Qur’an concerning the mission of the Generous Messenger.  And apart from that, Fakhr Razi has said: ‘The practical testimony is much better and stronger than the void aural testimony.’
But that some have said it is Allah’s tolerance of the testimony not acting it. This probability is also wrong, because what is the use of the tolerance of the testimony of unseen Allah? How can such a testimony be useful for them? In this case, the reference is to the unseen and the statement loses its degree of credit because the disbelievers have no access to prove it.
‘But the statement of:
وَمَنْ عِندَهُ عِلْمُ الْكِتَابِ
is enough to be a witness between you and I – a testimony to One that the knowledge of the Book is with Him.’
Some have said that the aim is Allah Himself; Fakhr Razi has reported this by Hassan Basri, Saeed bin Jabir and Zaj’jaj. Zamakhshari  and Fakhr Razi  have related it from Hassan Basri saying that:
لا و الله ما يعنى الا الله
‘By Allah, here, Allah has meant it Himself.’
And Siyu:ti says that: ‘Ibn Jarir and Ibn Monzar and also ibn Hatam have quoted Mojahid saying that: ‘The aim is Allah Himself.’ 
This probability is not correct either, first of all, it is opposite to the look of the text which denotes the contradiction, and secondly, turning the attribute into the abstract noun is wrong, as Fakhr Razi himself says, ‘It is not right to say: شهد بهذا زيد و الفقيه
‘Zaid and Faghih bore witness to this.’ And Faghih means Zaid himself, so it would be better to say: ‘The jurisprudent Zaid bore witness to this.’ 
And Al’lama Tabatabaee has specified this meaning by saying: ‘for this reason, Zamakhshari has paraphrased the Hassan’s statement and has changed the first sentence into the adjectival sentence and said:
كفى بالذى يستحق العبادة و بالذى يعلم علم ما فى اللوح المحفوظ الا هو شهيدا بينى و بينكم. 
‘He Who deserves to be worshipped is enough, and He Who has the Preserved Tablet with Him is the main One to be witness between you and I.’ And in this part, he, instead of the word “Allah”, the Exalted, which leads to the Essence of Allah, he has used the word الذى يستحق العبادة which is an attributive sentence. 
Surely Zamakhshari has done this to justify the immorality of the sentence, and in the mean time, to save and assure the commentary of Hassan Basri. But it must be noticed that replacing a word with another one of the same quality and meaning does not correct the first word. In here, the first word which leads to the Essence, is already in the Qur’an, therefore adding an adjective to it is hideous. Apart from this, as we mentioned it before, the aim of Allah’s testimony to the prophet-hood of the Messenger is within the verses and they all confirm the prophet-hood of that Holiness. In that case, it is better to relate those verses to the Holiness Essence of Allah which includes the whole Perfective Adjectives – not only by attributing, because the testimony of the Creator is above all the testimonies:
قال سبحانه: قل اى شىء اكبر شهادة قل الله شهيد بينى و بينكم. 
‘… Say, ‘What is the greatest witness?’ Say, ‘Allah is the Witness between you and I, (Qur’an: 6/19).’
And that Zaj’jaj ha said that: ‘It is not right for Allah that for the righteousness of His command to ask for another one’s testimony, because as Fakhr Razi says, ‘How is it permissible to Allah for confirming the righteousness His statement to swear to figs and olives as: و التين و الزيتون – it is not permissible to the learned of a book to ask a witness to it.’ 
The second probability is that the aim of swearing might be the ‘the book of the figs and olives’ and the aim of ‘the learned’ might be the Jews and the Christians; on these basis Siyu:ti says: ‘Ibn Jarir, through Aufa, relates from ibn Abbas that he was asked who is:
و من عنده علم الكتاب؟
‘And who is he with him the knowledge of the Book is?’
هم اهل الكتاب من اليهود و النصارى 
‘They are the people of Book from the Jews and the Christians.’
It is because the Jews and Christians have read about the signs of the prophetic mission of the Last Messenger in the Bible and Torah, and also they have learned whatever the messengers have preached about.
Nor is this probability correct, because in the blissful verse, He has mentioned: the Learned on the Book, but not only the Learned. And as it was mentioned before, this verse was revealed to Messenger in Mecca, and at that time, not a single man of the Jews or Christians believed in the Messenger of Allah nor did they bore witness to his prophetic mission.
The combat and campaign of the Holiness Messenger of Allah and his invitation in Mecca was only with the disbelievers of the Quraish, therefore, it is not correct that the Messenger of Allah had disputed to get one’s testimony for approving his prophet-hood. And some people have said: ‘The meaning of the testimony in this verse is the tolerance of the testimony but not the testimony itself, and tolerance of the testimony does not necessarily mean, the witness, at that time of witnessing, must believe in the prophetic mission. Therefore, the meaning of ‘the Learned on the Book’ is the scholars of the Jews and Christians that according to the Bible and Torah, have tolerated such testimony though have not believed yet.’ 
This probability is also wrong, because in this way, the reference that the Messenger of Allah is disputing is the disbelievers of the Quraish is that he disputes of the knowledge of the learned, though they have believed yet and have not accept his prophet-hood. And the testimony of one who does not believe and never has confessed cannot be correct. And if this meaning is acceptable it would be better the Messenger of Allah would refer the knowledge of the disbelievers because the miracles and proofs of the Qur’an were clear to them. That is, he should ask for their testimony for his Messenger-hood, but why did he deviate to the tolerance of the testimony of the people of the Book? While the disbelievers were partners to them in denying the Messenger-hood and the disbelief.
Apart from this, previously we said: ‘The aim of witnessing is confessing it, not tolerating it, because the tolerance of it for Allah, the Honourable and Exalted, is not an excuse for the disbelievers to go after the unseen.
The third probability is that the purpose of all: ‘the Book, the Preserved Tablet’ and the learned on the Book is only Gabriel. Siyu:ti says: ‘Ibn Abi Hatam has extracted a narrative from Saeed bin Jabir that he has said in the commentary of this verse:
من عنده علم الكتابِ جِبريل. 
‘He who has the knowledge of the Book is Gabriel.’
Nor is this probability correct
Nor is this prospect correct, because what is the use of Gabriel for the disbelievers who do not believe him and his testimony is nothing but mere promising the unseen and turning away from argumentation? Therefore, if the Messenger, instead of Gabriel, had asked for the testimonies of all the messengers: Michael, Seraph, Israel and the rest of the higher ranking angels, would be useless for the disbelievers.
The fourth probability is that, the meaning of: the People of the Book, might be the scholars of the Jews and Christians who have believed and accepted the prophetic mission of the Holiness Messenger: such as Abdullah bin Salam, Salman Farsi, Jaroud and Tamim.  Siyu:ti says: ‘Abdur Raz’zaq, ibn Jarir, ibn Monzar and ibn abi Hatam have quoted Ghatada saying:
كان من اهل الكتاب قوم يشهدون بالحق و يعرفونه، منهم عبد الله بن سلام و الجارود و تميم الدارى و سلمان الفارسى. 
Anyhow, this statement is also wrong, because all these people embraced Islam in Medina, while the blissful verse:
قل الله شهيد بينى و بينكم و من عنده علم الكتاب
has been revealed in Mecca; therefore, it does not sense: the Messenger of Allah has argued with the disbelievers of the Quraish in Mecca then he has the people of Medina to bear witness for his prophetic mission!
And the statement of some people who have said: ‘The revelation of this verse in Mecca is not inconsistent with the future testimony,’ is meaningless. This kind of argument is no longer valid and is too weak to be accepted, it is stated when a group of people say: لست مرسلا ‘You are not the Messenger of Allah.’
If it is answered: I am the Messenger of Allah, because a few years later, in Medina, some of the learned and expert on the Book will agree with my prophetic mission – so it is clear how baseless is the subject. 
The fifth probability is that:
(Concerning Abdullah bin Salam who was of the scholars of the Jews in Medina then when the Messenger of Allah migrated there he embrace Islam).
Siyu:ti says: ‘Ibn Sa‘d, ibn Abi Shiba, ibn Jarir and ibn Monzar have extracted it from Mojahid saying that:
انه كان يقرا: «و من عنده علم الكتاب»، قال: هو عبد الله بن سلام. 
And the orators who say: ‘this verse is about Abdullah bin Salam,’ are exaggerating it, because this statement is also void and baseless. As we already said, the Verse 13th, the Thunder is Meccan whereas Abdullah bin Salam has embraced Islam in Medina, so asking for his testimony against the disbelievers of Mecca is a kind of escaping from the argument: God forbid it!
Some people say: ‘The revelation of a chapter in Mecca is not inconsistent with some verses of it to be in Mena, it is possible that all verses of the chapter 13th, Ar-Rad, to be revealed in Mecca but only this verse has been Medina for the honour of Abdullah bin Salam. The answer is that only probable and possible cannot confirm the verse to be of Meccan, there must be a reasonable and reliable proof to verify the fact. Here, apart from that there is no such a proof, all the scholars have accepted that this verse is Meccan – as it is also related from BAHR. 
And Siyu:ti says: ‘Saeed bin Mansoor, ibn Jarir, ibn Monzar, ibn Abi Hatam and Nohhas in in hisbook of “NASIKH” have quoted Saeed bin Jabir saying that:
سئل عن قوله: و من عنده علم الكتاب أ هو عبد الله بن سلام رضى الله عنه؟ قال: و كيف و هذه السورة مكية؟! 
‘When they asked Saeed bin Jabir: ‘Is the purpose of saying ‘the scholars on the Book’ Abdullah bin Salam?’ He answered: ‘How can it be true when the chapter 13th has been revealed in Mecca?’
And ibn Abd-ul-Birr explains the biography of Abdullah bin Salam thus:
و قد قيل فى قول الله عز و جل: و من عنده علم الكتاب- هو عبد الله بن سلام- و انكر ذلك عكرمة و الحسن و قالا: كيف يكون ذلك و السورة مكية و اسلام عبد الله بن سلام كان بعد. 
In the verse, it has been said that the aim of the learned of the Book is Abdullah bin Salam, however, Ekrama and Hassan Basri have rejected this and have said: ‘How can it be true while we know that the chapter has been revealed in Mecca but the belief of Abdullah bin Salam was after that event.’
And Siyu:ti says: ‘Ibn Monzar has extracted the narrative and said:
ما نزل فى عبد الله بن سلام- رضى الله عنه- شيىء من القرآن. 
‘Concerning Abdullah bin Salam, there has been revealed no verse in the Qur’an.’
And also Siyu:ti says: ‘Abdur-Razzaq and ibn Monzar have quoted Zohri saying:
كان عمر بن الخطاب شديدا على رسول الله صلى الله عليه و آله و سلم، فانطلق يوما حتى دنا من رسول الله صلى الله عليه و آله و سلم و هو يصلى فسمعه و هو يقرا: «و ما كنت تتلو من قبله من كتاب و لا تخطه بيمينك اذا لارتاب المبطلون- حتى بلغ- الظالمون». و سمعه و هو يقرا: «يقول الذين كفروا لست مرسلا- الى قوله- علم الكتاب»، فانتظره حتى سلم فاسرع فى أثره فاسلم. 
[Zohri] says: ‘Omar bin Khat‘tab was a strict enemy to the Messenger of Allah, it was always the same, until once he went to the Messenger of Allah and heard that he was reciting this verse that Allah had addressed him: “You did not recite of the Book before your prophetic mission! You did not write anything with your hands! If it were the other way round, the disbelievers would doubt about you, (and they would interpret your prophet mission to be through your knowledge).”’
He eavesdropped more and heard that the messenger was reciting this verse: “The disbelievers say: ‘You are not the Messenger of Allah;’ so say: ‘The most sufficient witness of mine is Allah, the One with whom is the knowledge of the Book.’”
Omar waited until the prayer of the Messenger ended, then, he got closer and embraced the Islam at once.
Everyone knows that Omar’s embracing the Islam was in the year 6th in Mecca, and it is why the verse ‘كفى بالله شهيدا’ has been revealed in Mecca but not in Media – so it has nothing to do with Abdullah bin Salam.
Apart from all these, as we already explained it in details, it became clear that all verses of the chaoter 13th, Ar-Ra‘d are joined to each other and made a chain, and this verse is supervising the first verse and the verse 19th, and also it is an answer to the disbelievers in the verse 7th and twenty-seven; it is in a way that the result of the chapter is drawn only from this verse. It is quite out of place that the whole chapter to be revealed in Mecca but the ending verse of it, years later, in Medina. It is strange that some people such as Abu-as-So‘oud,  ibn Teimi‘ia  have claimed that this verse had been revealed in Medina.
The sixth probability is that the aim of the Book may be the Glorious Qur’an, and the purpose of the learned on the Book may be the learned on the Glorious Qur’an – but this statement is irrational.  It means that one has tolerated the meaning of this Qur’an and then has been allocated to its knowledge. He is a witness and says that: ‘It is from Allah and I am the Messenger of Allah; in this way, the last verse of the chapter runs the first verse where He states:
تلك آيات الكتاب و الذى انزل اليك من ربك الحق
‘These are the verses of the Book and they are revealed you from your Lord in truth.’
And also this verse, in the middle of the chapter, says:
افمن يعلم انما انزل اليك من ربك الحق كمن هو اعمى
What! Is one who knows what has been revealed to you from your Lord is the Truth, like someone who is blind?
In fact, this testimony of the learned on the Glorious Qur’an to the disbelievers is an emphasis by Allah to state the truthfulness of the Book and the prophet-hood of the Messenger against the disbelievers; He has stated it twice:
لو لا انزل عليه آية من ربه
‘Why is not sent to him an odd and strange miracle from his Lord?’ Here, they said: ‘لست مرسلا’ ‘You are not a Messenger at all.’
So far, their questions have been answered that: In this miraculous Qur’an, my Allah has testified my prophetic mission; and the scholar on the Qur’an has also testified my prophet-hood. And this is the best proof that this verse has been revealed in Mecca. It emphasizes the most narratives that have been related by the Sunnite and the Shiite; and also makes it clear that the purpose of the learned of the Book is the Holiness Commander of the believers, Ali bin Abī Tālib, Upon Him be Peace, and after that Holiness, the Imams from the Household, Upon Him be Peace.
By the Sunnite’s side, Tha‘labi by his own documents quotes Muhammad bin Hanifa,  and also Abu Naeem Isfahani by his documents quotes Muhammad bin Hanifa;  and by the Shiite’s side, Saffar in “ BASAER AD-DARAJAT”, by his own documents quotes Abu Hamzah Thomali  quoting the Holiness Imam Bāqir, Upon Him be Peace, and also Saffar, by means of his documents from Fazil bin Yasar quotes the Holiness Imam Bāqir, Upon Him be Peace.  By means of his documents from Fazil bin Yasar, Ayyashi quotes the Holiness Imam Bāqir, Upon Him be Peace,  that has stated:
هذه الآية نزلت فى على بن أبى طالب.
‘This verse has been revealed concerning Ali bin Abī Tālib.’
And in these two recent narratives he adds:
و انه عالم هذه الامة بعد النبى.
‘And indeed he is the most learned of this nation after the Messenger.’
All these five narratives explained that this verse has been revealed about Ali bin Abī Tālib, and in the recent two narratives he adds that after the Messenger of Allah, Ali bin Abī Tālib is the most learned of this nation.
And by means of his documents from Jabir, Barid bin Mua‘wiyah and Fazil bin Yasar quotes the Holiness Imam Bāqir, Upon Him be Peace, and also by means of his documents from Abdullah bin Bokair and Abdullah bin Kathir Hashimi quotes the Holiness Imam Sādiq, Upon Him be Peace, and finally, by his documents from Salman Farsi who has quoted the Commander of the believers, Upon Him be Peace, that this verse has been revealed concerning the Commander of the believers, Upon Him be Peace. 
And the Hanafian Ghandouzi quotes Tha‘labi and ibn al-Maghazeli who, by means of their documents quote Abdullah bin Attar has related:
قال: كنت مع محمد الباقر- رضى الله عنه- فى المسجد فرايت ابن عبد الله بن سلام، فقلت: هذا ابن الذى عنده علم الكتاب؟ قال: انما ذلك على بن أبى طالب. 
[Abdullah A’ta] syas: ‘We were in the mosque with Bāqir, Upon Him Peace, when I saw the son of Abdullah bin Salam and asked the Holiness: ‘Is he the son of one who has the full knowledge of the Book?’ The Holiness stated: “He who has the full knowledge of the Book is Ali bin Abī Tālib.”
And Hakim Hasekani, by means of his documents, has quoted Abu Sa’eed Khedri:
قال: سالت رسول الله صلى الله عليه و آله و سلم عن قول الله تعالى: و من عنده علم الكتاب. قال: ذاك اخى على بن أبى طالب. 
Abu Sa’eed] says: I asked the Messenger of Allah, Bless be to Him and his Descendants, concerning this verse, and He stated: “The most learned man in the Book is my brother, Ali bin Abī Tālib.”
And Hakim Hasekani has quoted Abi Salih:
قوله عز و جل: و من عنده علم الكتاب. قال رجل من قريش: هو على و لكنه لا نسميه. 
[Abu Salih] says: The meaning of this و من عنده علم الكتاب is a man from Quraish, that is: Ali bin Abī Tālib, however, we do not mention his name.
And it is related from the same Abu Salih, Hasekani who says:
و من عنده علم الكتاب. قال: على بن أبى طالب، كان عالما بالتفسير و التاويل و الناسخ و المنسوخ و الحلال و الحرام. 
[Abu Salih] said: ‘The most learned in the Book, in the blissful verse, is Ali bin Abī Tālib, who is the most learned in the commentary, the decider between the two abrogating and repealing, the permitted and the unpermitted ones.’
Ghandouzi, the Hanafian, has related the similar one from ibn Abbas. 
And from the sides of the Sunnite and the Shiite, ibn Shar Aashub has quoted Muhammad bin Moslim, who has quoted Abu Hamza Thimali, and he has quoted Jabir bin Yazid, and he also quoted the Holiness Imam Bāqir, Upon Him be Peace, and that Holiness has quoted Ali bin Fazzal and Fazil bin Yasar and Abu Basir, who have quote the Holiness Imam Sādiq, Upon Him be Peace, and Ahmad bin Halabi, and Muhammad Fazil has quoted the Holiness Imam Reza, Upon Him be Peace, and also Musa bin Ja‘far, and Zeid bin Ali, and Muhammad bin Hanafiia, who has quoted Salma Farsi and Abu Saeed Kheri and Ismail Suddi:
انهم قالوا فى قوله تعالى: قل كفى بالله شهيدا بينى و بينكم و من عنده علم الكتاب، هو على بن أبى طالب 
‘That all of those [companions] have said the statement of Him, the Exalted this verse: ‘Say, ‘Allah is sufficient as a Witness between you and I, and so is one who has the knowledge of the Book’, means: Ali bin Abī Tālib.’
And in his commentary, ibn Shahr Aashub quotes Tha’labi, and he quotes Abdullah bin A’ta, who quotes the Holiness, Imam Bāqir, Upon Him be Peace, relating that: ‘Some people have believed that the phrase ‘the learned in the Book’ is about Abdullah bin Salam, but he is Ali bin Abī Tālib.’
And when it was said in the presence of Saeed bin Jabir ‘the learned in the Book’ is Abdullah bin Salam, he rejected it by saying: ‘No, this verse has been sent down in Mecca.’ And it is related from ibn Abbas saying: ‘No, by Allah, the aim in this phrase is Ali bin Abī Tālib, who was the most learned in the Book, the commentary, interpretation, abrogating and repealing.’
And it is related from ibn Hanafiia that the knowledge of the Book is with Ali – from the beginning to the end.
Whatever Tha’labi has related by the Sunnite and the Shiite concerning the revelation of this verse is related to the Commander of the believers, Ali, Upon Him be Peace, Naziri has only related it by the Sunnite in “Khasais”. 
And Sheikh Ali bin Yunus Nabati Aamoli has said it in the book of “The Straight Path” that: ‘It is related in the commentary of ibn A’ta that: ‘When I saw the son of Slam I said: The knowledge of the Book used to be with his father. He stated: ‘No, it was with Ali bin Abī Tālib.
And Abu Naeem Isfani has related similar narrative in two different ways from Muhammad Hanafiia, and then Tha’labi has said: ‘This narrative is related to ibn Omar, to Jabir, to Abu Horaira and to Aisha;’ 
And the jurisprudent, al-Moghazeli Shafiee, by means of his documents quotes Ali bin Habis who has related: ‘Abu Matyam and I went to Abdullah bin A’ta , Abu Maryam told Abdullah: ‘The narrative which you related to me fro the Holiness Imam Bāqir, Upon Him be Peace,, do relate it to Habis, please.’ Ibn A’ta said: ‘I was in the presence of the Holiness Imam Bāqir, Upon Him be Peace, when the son of Abdullah passed by. Right then, I said the Holiness: ‘May I be made your sacrifice, he is the son of a man who holds the whole knowledge of the Book.’
The Holiness answered: “Never! The most learned in the Book is your Master, Ali bin Abī Tālib:
و من عنده علم الكتاب، افمن كان على بينة من ربه و يتلوه شاهد منه، انما وليكم الله و رسوله و الذين آمنوا. 
And Muhammad bin Ya‘qub Kolaini, by means of his documents from Boraid bin Mua‘wiyah,  also Ayyashi in his commentary from Boraid bin Mua‘wiyah,  and also Saffar in “Basaeer ad-Darajat”, by his documents from Boraid bin Mua‘wiyah  have related that:
قال: قلت لابى جعفر عليه السّلام: قل كفى بالله شهيدا بينى و بينكم و من عنده علم الكتاب. قال: ايانا عنى، و على افضلنا و اولنا و خيرنا بعد النبى صلى الله عليه و آله و سلم.
Boraid bin Mua‘wiyah says: ‘I asked the Holiness Imam Bāqir, Upon Him be Peace, about the occasion of the revelation of the verse
و من عنده علم الكتاب
The holiness answered: ‘In this verse, Allah has mentioned us, and among us, Ali bin Abī Tālib, Upon Him be Peace, is the best after the Messenger of Allah, Bless be to Him and his Descendants.' And Sheikh Sadough ibn Babwiiah, by means of his documents fro Ateiia Aufi quoting Abu Saeed Khodrin, has related:
قال: سالت رسول الله عن قول الله جل ثناؤه قال الذى عنده علم من الكتاب. قال: ذاك وصى اخى سليمان بن داود. فقلت له: يا رسول الله فقول الله: قل كفى بالله شهيدا بينى و بينكم و من عنده علم الكتاب؟ قال: ذاك اخى على بن أبى طالب . 
[Abu Saeed] says: 'I asked the Messenger of Allah concerning the verse: "الذى عنده علم من الكتاب" and he answered: 'Its descention in the honour of the Successor of my brother, Soleiman bin Dawood.’ I had the honour to ask: ‘O the Messenger of Allah, what it means:
و من عنده علم الكتاب؟
He stated: ‘It is my brother, Ali bin Abī Tālib.’
 Surah 13, "رعد", Verse 43.
 The commentary of " ابو الفتوح", volume 6, page 503.
 The Commentary of ‘Kash’shaf, volume 2, page 536.
 "تفسير فخر" 'The Commentary of Fakhr-e-Razi', volume 19, page 69.
 This word is correct, but against the disbelievers who do not agree with the rightfulness of the Messenger of Allah, Bless be to Him and his Descendants, in the Qur'an, it must be said that: as the Qur'an is a miracle and Allah has sent it down through the Generous Prophet, Bless be to Him and his Descendants, it means that He has approved him – and this performance of the miracle of the Messenger is by Allah and He is the witness to it. Thus, in this way, the nonsense of Fakh-e-Razi can be answered!
 "تفسير فخر رازى" 'The Commentary of Fakhr-e-Razi', volume 19, page 70; and he has brought this statement from Hassan, Zah'hak and Saeed bin Jabir in the commentary of "مجمع البيان", volume 3, page 301. And he has said: Zaj'aj has chosen it, and a good witness to it is the one who has recited it: " و من عنده علم الكتاب يا و من عنده علم الكتاب". And in the commentary of Kash'shaf, volumes 2, page 536 he says: the recitation of him who has pronounced the word " مِن" with the lower case sound, confirms Hassan's claim, as: "اى من لدنه علم الكتاب". Or that the word " علِم" is the verb serving the object, as: " من عنده علم الكتاب".
"تفسير كشاف" 'The Commentary of Kash'shaf', volume 2, page 536.