Talmudic scholar who wrote a codification of the Talmud known as Sefer ha-Halakhot (“Book of Laws”), which ranks with the great codes of Maimonides and Karo.

Alfasi lived most of his life in Fès (from which his surname was derived) and there wrote his digest of the Talmud, the rabbinical compendium of law, lore, and commentary. In 1088 two of his enemies denounced him to the government on an unknown charge. He fled to Spain, where, in Lucena, he became head of the Jewish community and established a noted Talmudic academy. Alfasi provoked a rebirth of Talmudic (Talmud and Midrash) study in Spain, and his influence was instrumental in changing the centre of such studies from the Eastern to the Western world.

His codification deals with the Talmud's legal aspects, or Halakha (Halakhah) (Hebrew Law), including civil, criminal, and religious law. It omits all homiletical passages as well as portions relating to religious duties practicable only in Palestine. He performed a great service by concentrating on the actual text, which had been neglected. His commentaries summarize the thought of the geonim who presided over the two great Jewish academies in Babylonia between the middle of the 7th and the end of the 13th century. In addition, his work played a major role in establishing the primacy of the Babylonian Talmud, as edited and revised by three generations of ancient sages, over the Palestinian Talmud, the final compilation of which had been interrupted by external pressures. Alfasi's Sefer ha-Halakhot is still important in yeshiva studies.