 This event is mentioned in Ibn Ishaq's biography of Muhammad. Most of the information available about the events is derived from the sira — maghazi traditions (biographical narratives and documentation of military campaigns) of the early centuries of Islam. The general sequence of the events gained consensus early on, as demonstrated in the text of Ibn Ishaq, an early biographer of Muhammad. Accounts of the battle are derived mainly from descendants of the participants. Much of the basic narrative and chronology, according to Robinson, is reasonably authentic, although some of the more elaborate details — such as the exact scale of the Muslim defeat — may be doubtful or difficult to ascertain.
