Much like the earliest sources for Jesus and the Buddha, the earliest account of the life of Muhammad (ca. 570–632) comes from oral traditions passed down among followers. According to these traditions, at about age forty, Muhammad had a vision of an angelic being who commanded him to preach the revelations that God would be sending him. Muhammad began to preach to the people of Mecca, urging them to give up their idols and to submit to the one indivisible God. After his death, scribes organized the revelations jotted down by followers or memorized into chapters. In 651 they published the version of them that Muslims consider authoritative, the Qur’an (kuh-RAHN).

For the first two or three centuries after the death of Muhammad, there was considerable debate about theological and political issues. Likewise, religious scholars had to sort out and assess the hadith (huh-DEETH), collections of the sayings of or anecdotes about Muhammad. Muhammad’s example as revealed in the hadith became the legal basis for the conduct of every Muslim. The life of Muhammad provides the “normative example,” or Sunna, for the Muslim believer. Muhammad’s example became central to the Muslim way of life.