("Book of Creation"). Hebrew treatise on cosmogony and cosmology, originating from the third or fourth century. Several versions of the work are extant, differing considerably from each other. Its purpose is to describe the basic principles by which God created the world and by which the world continues to operate. At the same time, certain mystical elements can be found in it and the author's terminology served as a source of symbols for the medieval Jewish mystics (see Mysticism).
The world was created, according to this work, through the combination of two principles: the ten Numbers from one to ten and the 22 letters of the Hebrew Alphabet. Ten Divine utterances brought about the existing cosmos and the combined force of the numbers and letters contains in it all existence. The ten numbers are called in this work Sefirot, an original term, and they are described as the five infinite dimensions or ten directions of the cosmos---East, West, North, South, Up, Down, Beginning, End, Good and Evil; they are also the stages by which the three elements (Fire, Water and Air) evolved. The sefirot, however, are also entities which worship God and kneel before His throne.
The letters of the alphabet are divided by the author into three groups: Three "mothers"---aleph, mem, and shin, representing the three elements; seven "double" letters, i.e., letters which can be pronounced in two different ways---bet, gimel, dalet, kaf, peh, resh (in the Bible, the resh is punctuated several times with a dagesh kal, which is used to change pronunciation) and tav; the remaining 12 are "simple" letters. In succinct sentences, the author describes the meaning of each group of letters in cosmic terms and in the realms of anthropology and psychology.
Sefer Yetsirah presents the earliest Hebrew grammatical system, long before Jewish scholars, following Arabic models, systematized Hebrew linguistics. According to Sefer Yetsirah, all Hebrew words are based on two-letter roots, of which there are 231. Creation and the existence of the world are based on combinations and permutations of these roots.
It is not clear whether the book was intended to serve as a manual for scholars and mystics in creating various beings. Many medieval commentators used it to direct their readers in the creation of a Golem. The earliest commentators, however, employed it as a work of science---Saadiah Gaon, Shabbetai Donolo,
