In the Introduction to Text and Interpretation: Imam Jaʿfar al-Ṣādiq and His Legacy in Islamic Law, Hossein Modarressi introduces the topic of his study: the early development of the Jaʿfarī Islamic legal school. Modarressi notes that the Jaʿfarī school emerged in the late Umayyad period (i.e., the first half of the second Islamic century/mid-eighth century CE) and its eponym was Imam Abū ʿAbd Allāh Jaʿfar b. Muḥammad al-Ṣādiq (d. 148/765), a preeminent jurist of Medina and a revered member of the House of the Prophet (ahl al-bayt). Over the course of the Introduction, Modarressi draws on various sources to show how Imam al-Ṣādiq was revered by many as a leading jurist during his time. Modarressi notes that his project utilizes “all material that corresponds to the language and character of Jaʿfar al-Ṣādiq, as known through both historical and biographical accounts, and as such can reasonably be deemed reliable,” without regard to sectarian tendencies and doctrinal affiliations (p. 11).
This source is part of the Online Companion to Hossein Modarressi, Text and Interpretation: Imam Jaʿfar al-Ṣādiq and His Legacy in Islamic Law (Harvard University Press, 2022).