And both are in common in denying Jesus Christ, the sure sign of an antichrist religion:
1 John 4:1-3
Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world. By this you know the Spirit of God: Every spirit that confesses that Jesus Christ has come in the flesh is of God, and every spirit that does not confess that Jesus Christ has come in the flesh is not of God. And this is the spirit of the Antichrist, which you have heard was coming, and is now already in the world.
This is more of a theory of course. Muhammed is quoted as saying he baracaded himself in a cave for three days and was visited by an angel (who really was the angel Lucifer or Satan).
Felix also locked himself in his room for three days under heavy study.