SAʿADYAH GAON (882–942), properly Saʿadyah ben Yosef al-Fayyumī, was a Jewish theologian, jurist, scholar, and gaon ("head, eminence") of the rabbinic academy at Sura, Babylonia. Saʿadyah was born in Dilaẓ (modern Abu Suwayr) in the Faiyūm district of Upper Egypt. Virtually nothing is known about his family and early education. By age twenty-three, however, he had corresponded with the noted Jewish Neoplatonist Yitsḥaq Israeli (c. 855–955), published the first Hebrew dictionary (Sefer ha-agron), and composed a polemic against the Karaite schismatic ʿAnan ben David (fl. 760). After leaving Egypt, Saʿadyah spent time in both Palestine and Syria but eventually, in 921 or 922, settled in Babylonia. There he championed the cause of the Babylonian rabbis in a dispute with Palestinian authorities over fixing the religious calendar and published his views in two treatises, Sefer ha-zikkaron and Sefer ha-moʿadim...