Obadiah ben Abraham Maimonides (1228–1265), one of the three known grandchildren of Moses Maimonides, was a pietistic mystic who lived in Cairo. Very little is known about him, the only substantial account having been written in the seventeenth century by the Egyptian Jewish chronicler Joseph Sambari. More is known about his elder brother David (1222–1300), who succeeded their father, Abraham, as head of Egyptian Jewry (Heb. nagid; Ar. raʾīs al-yahūd). Although mentioned together with David in a letter found in the Cairo Geniza as one of “the two great luminaries, the two tab…