Surah 16. An-Nahl, Ayah 103

I.e., to Muhammad - thus insinuating that his claim to divine revelation was false.

Whereas some of the pagan Quraysh regarded the ideas expressed in the Qur'an as "invented" by Muhammad, others thought that they must have been imparted to him by a foreigner - perhaps a Christian - who lived in Mecca at that time, or whom the Prophet was supposed to have encountered at an earlier period of his life. Various conjectures have been advanced - both by early Muslim commentators and by modern orientalists - as to the "identity" of the person or persons whom the suspicious Meccans might have had in mind in this connection but all these conjectures are purely speculative and, therefore, of no historical value whatever. The suspicion of the pagan Meccans implies no more than the historical fact that those of the Prophet's opponents who were unwilling to pay him the compliment of having "invented" the Qur'an (the profundity of which they were unable to deny) conveniently attributed its authorship - or at least its inspiration - to a mythical non-Arab "teacher" of the Prophet.

For an explanation of this composite rendering of the descriptive term mubin, see surah {12}, note [2]. The term is used here to stress the fact that no human being - and certainly no non-Arab - could ever have produced the flawless, exalted Arabic diction in which the Qur'an is expressed.

 Some Meccan pagans claimed that the Prophet (ﷺ) received the Quran from a non-Arab slave owned by an Arab pagan.

The wicked attribute to Prophets of Allah just such motives and springs of action as they themselves would be guilty of in such circumstances. The Pagans and those who were hostile to the revelation of Allah in Islam could not and cannot understand how such wonderful words could flow from the tongue of the Holy Prophet. They must need to postulate some human teacher. Unfortunately for their postulate, any possible human teacher they could think of would be poor in Arabic speech if he had all the knowledge that the Qur-an reveals of previous revelations. Apart from that, even the most eloquent Arab could not, and cannot, produce anything of the eloquence, width, and depth of Quranic teaching, as is evident from every verse of the Book.