Sefer Yeṣirah and Its Contexts: Other Jewish VoicesSefer Yeirah, or Book of Formation, is one of the most influential Jewish compositions of late antiquity. First attested to in the tenth century C. E. and attributed by some to the patriarch Abraham himself, Sefer Yeirah claims that the world was created by the powers of the decimal number system and the twenty two letters of the Hebrew alphabet. This short, enigmatic treatise was considered canonical by Jewish philosophers and Kabbalists and has