Judah ha-Kohen Rosh ha-Seder

Judah ben Joseph ha-Kohen Rosh ha-Seder, an Egyptian scholar active in the middle of the eleventh century, was a leading halakhic authority of his day. He was related to the family of several Palestinian geonim. During his life, Judah was known simply as ha-rav (the master), an honorific that bespeaks his singular standing. He wrote biblical and talmudic commentaries, and several of his legal responsa survive in the Cairo Geniza. Judah’s Judeo-Arabic The Book of Years (Kitāb al-isnān) survives only in short fragments, and even its name is uncertain (some scholars prefer The Book of Man, Kitāb al-insān). Much of the surviving work concerns the laws of maturity, the subject of a similar monograph by Samuel ben Ḥofni Ga’on.