Rav Hai Gaon’s Jurisprudential Monograph Kitāb Adab al-Qaḍā: A Reconstructed Text from the Cairo Genizah

This essay presents the discovery of a previously almost entirely unknown treatise written in Judeo-Arabic by Rav Hai b. Sherira Gaon. This monograph, a manual for judges, is a Jewish instantiation of the well-established Muslim genre Adab al-Qāḍī (Duties of Judges). To date, only several indirect remnants translated into medieval Hebrew have been identified as part of this work; however, large parts of the skeleton of this halakhic monograph can be reconstructed from Genizah fragments. Not only is this work of immense importance with respect to judicial issues, but it also promises to elucidate aspects of halakhic literature written in Judeo-Arabic generally. After presenting the historical-philological thinking that led to this discovery, this article considers the text’s importance and the social-literary circumstances that led to its development within its Islamic context. The Islamic and Jewish texts of the genre lead to the adoption of a more detailed model of the mutual shared legal relationships between Jews and Muslims in medieval Babylonia and yield what may be viewed as a more complicated and nuanced approach to the monotheistic-Abrahamic triangle.