Muhammad is the central figure in Islam. Chosen by God to receive the revelation of the Quran, he has been taken by all Muslims to be the ideal man, the perfect embodiment of what it means to be a Muslim. Material on the life of Muhammad is available in ample if, in fact, not excessive quantities. The earliest complete extant text stems from a version of the biography of Muhammad by Ibn Ishaq edited by Ibn Hisham. Muslims created several methods of evaluating the isnads, using criteria which dealt in particular with the life and character of the individual transmitters found in the sequence of names. The picture of Muhammad has, as a result of the notion of sinlessness, been subject to all sorts of "fantastic" elaborations, creating a mythic image of the prophet of Islam. More prominent in this elaboration of the picture of Muhammad is the story of his night journey to Jerusalem and his ascension into heaven.