Sepher Yetzirah or The Book of Creation

The "Sepher Yetzirah," although this name means "The Book of Formation," is not in any sense a narrative of Creation, or a substitute Genesis, but is an ancient and instructive philosophical treatise upon one aspect of the origin of the universe and mankind; an aspect at once archaic and essentially Hebrew. The grouping of the processes of origin into an arrangement, at once alphabetic and numeral, is one only to be found in Semitic authors. Attention must be called to the essential peculiarity of the Hebrew language, the inextricable and necessary association of numbers and letters; every letter suggesting a number, and every group of letters having a numerical signification, as vital as its literal meaning. The Kabalistic principles involved in the reversal of Hebrew letters, and their substitution by others, on definite schemes, should also be studied and borne in mind. It is exactly on these principles that the "ground-work idea" 'of this disquisition rests; and these principles may be traced throughout the Kabalistic tractates which have succeeded it in point of time and development, many of which are associated together in one volume known as the "Zohar," which is in the main concerned with the essential dignities of the Godhead, with the Emanations which have sprung therefrom, with the doctrine of the Sephiroth, the ideals of Macroprosopus and Microprosopus, and the doctrine of Re-incarnation. The "Sepher Yetzirah," on the other hand, is mainly concerned with our universe and with the Microcosm. The opinions of Hebrew Kabalistic Rabbis and of modern mystics may be fitly introduced here. This book mentions a very special Hebrew scholar;  the Vilna Gaon or Elijah of Vilna and simply by as Gra ("Gaon Rabbenu Eliyahu") whose study and interpretation of the "tree of life" is unique and notable.