Sefer Yetzirah
An intimate relation exists between the "Sefer Yetzirah" and the later mystics; and although there is a marked difference between the later Kabbalah and the "Sefer Yetzirah" (for instance, the "sefirot" of the Kabbalists do not correspond to those of the "Sefer Yetzirah"), the system laid down in the latter is the first visible link in the development of Kabbalistic ideas. Instead of the immediate creation "ex nihilo", both works postulate a series of emanations of mediums between God and the universe; and both consider God as the first cause only, and not as the immediate efficient cause of the world.