Sefer Yetzirah: The Book of Creation – In Theory and PracticeAryeh Kaplan
is the title of the earliest extant book on Jewish esotericism, although some early commentators treated it as a treatise on mathematical and linguistic theory as opposed to Kabbalah. “Yetzirah” is more literally translated as “Formation”; the word “Briah” is used for “Creation”. The book is traditionally ascribed to the patriarch Abraham, although others attribute its writing to Rabbi Akiva. Modern scholars haven’t reached consensus on the question of its origins. According to Rabbi Saadia Gaon, the objective of the book’s author was to convey in writing how the things of our universe came into existence.