It has been suggested that the captivity of the Jews in Babylon led to the formation of this philosophy by the effect of Chaldean lore and dogma acting on Jewish tradition.
there is no proof that any part of it was written for centuries after. It has been kept curiously distinct both from the
Exoteric Pentateuchal Mosaic books, and from the ever-growing Commentaries upon them, the Mishna and Gemara, which form the Talmud. This seems to have grown up in Hebrew theology without combining with the recondite doctrines of the Kabalah. In a similar manner we see in India that the Upanishads, an Esoteric series of treatises, grew up alongside the Brahmanas and the Puranas, which are Exoteric instructions designed for the use of the masses of the people.
The "Sepher Yetzirah" or "Book of Formation" is the oldest treatise;