Isaac ben Jacob Alfasi (1013–1103) - also known as the Alfasi or by his Hebrew acronym, the Rif, was a Maghrebi Talmudist and posek. He is best known for his work of halakha, the legal code Sefer Ha-halachot, considered the first fundamental work in halakhic literature. His name "Alfasi" means "of Fez" in Arabic, but opinions differ as to whether he ever lived in Fez.

The Talmud is the central text of Rabbinic Judaism and the primary source of Jewish religious law (halakha) and Jewish theology. Until the advent of modernity, in nearly all Jewish communities, the Talmud was the centerpiece of Jewish cultural life and was foundational to "all Jewish thought and aspirations", serving also as "the guide for the daily life" of Jews.