Reputed author of "Kelimmat ha-Goyim," a work which attacks Christianity, probably written by Profiat Duran (Efodi) in 1349. The assumption is that the "Kelimmat ha-Goyim" is the same as the "Sefer ha-Kelimmah" mentioned by Joseph b. Shem-Ṭob, and that this is identical with the "Sefer ha-Kelimmah" by Reuben ha-Sefardi mentioned in Moses Botarel's commentary on "Sefer Yeẓirah" (end of mishnah 2, ch. ); but there is no doubt of the correctness of Zunz's view that "Reuben ha-Sefardi" and his "Sefer ha-Kelimmah" as well as the other work ascribed to him, "Sefer ha-Shulḥan," are all fictitious names, invented like many others by Botarel.