[montyspython]

I always thought the Koran was written by the Jews just as a joke to play on the Arabs.

[muawiyah]

There is a case to be made for the early Moslems encountering an old Torah buried in the desert that contained some anomalous material.

[Cronos]

There is an interesting study that the Koran is actually a Nestorian/Assyrian Christian text originally written in Syriac/Aramaic and not in Arabic.