The sīra authorities provide a mass of contradictory data on the chronology of the Prophet's raids and the task of fitting these inconsistencies into a cogent chronological pattern is beset with difficulties. In the main sources, for example, Mūsā b. ‘Uqba, Ibn Isḥaq, and al-Wāqidī, we find noticeable divergencies in the dating of a specific event. This is so even with important incidents such as the expulsion of Banu Qaynuqā‘and a comparatively late event such as the attack on Khaybar. A textual collation of the chronological material does suggest, however, that in some cases it may be possibleto win through to a safer position.