Sometimes stated to be a grandson of Isaac Alfasi. He is frequently cited as the author of "Sha'are Shebu'ot," a work in twenty chapters on oaths, usually printed with Alfasi's "Halakot" (Fürst, "Bibl. Jud." i. 36; Benjacob, "Oẓar ha-Sefarim," p. 605). It is probable, however, that the actual author was Isaac ben Reuben of Barcelona or an otherwise unknown Isaac ben Reuben, especially as he quotes the Rif without claiming relationship.

Bibliography: Steinschneider, Cat. Bodl. col. 1148;
Weiss, Dor, iv. 281.
A Song of Love by Isaac ben Reuben has been translated into English by Nina Davis in Jew. Quart. Rev. viii. 271.D.