Sefer Yereim (“The Book of those who Fear”) is a 12th-century legal work that incorporates ethical teachings, based on the enumeration of the 613 commandments in the Halakhot Gedolot. The work consists of 417 commandments, not 613, since some commandments are grouped together. In his introduction to the work, Rabbi Eliezer explains that he chose its title to reflect his intention that “from [this book], people will learn to fear God.” Later legal authorities often quote the Yereim and consider it authoritative.