Isaac ben Samuel ha-Sefaradi ibn al-Kanzī was a biblical exegete, halakhist, judge, and payṭan (liturgical poet) who was born either in al-Andalus or in Egypt to an Andalusī father. He is known from the Cairo Geniza to have been a judge of the Palestinian-rite court in Fustat from around 1090 to 1127. A member of the entourage of the nagid Mevorakh ben Saʿadya, he bore the titles “head of the house of study, aide of the exilarchate” (Aram./Heb. resh be rabbana ʿezer ha-nesiʾut) and “the great rabbi.”

In his responsa, Isaac ben Samuel provided answers to queries from as far away as Yemen. One of…