Unpublished article. R. Isaac ben Sheshet Perfet (1326-1408), the Ribash, was born in Barcelona (some say, Valencia) but emigrated in 1391 to North Africa and ended his days as a foremost Halakhic authority in Algiers.[1] His teachers were Nissim of Gerona, the Ran (d.c. 1375) and Peretz ha-Kohen (d.c. 1370). In his Responsa collection,[2] No.157…