Among the works of Kabbalism the Sepher Jetzirah is claimed to be the most profoundly occult. It is based on the twenty-two letters of the Hebrew alphabet, and developed a system or correspondences and numbers. The system asserts, principally, that God created the universe by the way of thirty-two paths of secret wisdom, using ten additional fundamental numbers (those out of which the entire universe evolved). The twenty-two letters follow these categories: three Mothers, seven double consonants, and twelve single consonants. A.G.H.
Riland, George, The New Steinerbooks Dictionary of Paranormal, New York, Warner Books, Inc., 1980, p. 147