IBN ṢA‛D [Abū ‛Abdallāh Maḥommed ibn Ṣa‛d ibn Mani‛ uz-Zuhrī], often called Kātib ul-Waqidī (“secretary of Waqidī”) of Baṣra] (d. 845), Arabian biographer, received his training in tradition from Waqidī and other celebrated teachers. He lived for the most part in Bagdad, and had the reputation of being both trustworthy and accurate in his writings, which, in consequence, were much used by later writers. His work, the Kitāb ul-Ṭabaqāt ul-Kabīr (15 vols.) contains the lives of Mahomet, his Companions and Helpers (including those who fought at Badr as a special class) and of the following generation (the Followers) who received their traditions from the personal friends of the Prophet.
This work has been edited under the superintendence of E. Sachau (Leiden, 1904 sqq.); cf. O. Loth, Das Classenbuch des Ibn Sa‛d (Leipzig, 1869). (G. W. T.)