By the star when it descends, Your companion [i.e., Muhammad] has not strayed, nor has he erred, nor does he speak from [his own] inclination.

     By the star when it descends, Your companion [i.e., Muhammad] has not strayed, nor has he erred, nor does he speak from [his own] inclination. It is not but a revelation revealed, taught to him by one intense in strength [i.e., Gabriel] - one of soundness. And he rose to [his] true form while he was in the higher [part of the] horizon. 

THE QUR'AN, an-Najm 53:1-7