Isaac Alfasi

Isaac Alfasi
Born1013 (1013)
Qal'at Bani Hammad, now in Algeria
Died1103 (aged 89–90)
Other namesRif
OccupationRabbi

Isaac ben Jacob Alfasi (1013–1103) (Arabic: إسحاق الفاسي, Hebrew: ר' יצחק אלפסי), also known as the Alfasi or by his Hebrew acronym, the Rif (Rabbi Isaac al-Fasi), was a Maghrebi Talmudist and posek (decider in matters of Halakha). He is best known for his halakhic legal work Sefer Ha-halachot, considered the first fundamental work in halakhic literature.