Sepher Yetzirah

The Sepher Yetzirah is one of the main and most important works of Kabbalah. Referenced by other works such as the Bahir, it is broken apart into a series of statements on the Hebrew alphabet and numeric systems. Among other concepts it expounds the concept of creation via the three mothers; Alef, Mem, and Shin, and their relative powers. It is one of the most integral works from which such types of occultism stem.