Muslims claim that because Muhammad was illiterate, he could not have written the Qur’an, and thus the Qur'an is a miracle, Muhammad's primary miracle. This idea of illiteracy is supported in the Qur’an:
Sura 7:157: "Those who follow the apostle, the unlettered Prophet, whom they find mentioned in their own (scriptures), - in the law and the Gospel...
Sura 7:158 – Say: "O men! I am sent unto you all, as the Apostle of God, to Whom belongeth the dominion of the heavens and the earth: there is no god but He: it is He That giveth both life and death. So believe in God and His Apostle, the Unlettered Prophet, who believeth in God and His words: follow him that (so) ye may be guided."
Thus, the Qur’an’s very existence is testimony to Muhammad’s status as a prophet. There are a couple of problems with this position.