“The Book ‘Iyyun itself makes no mention at all of primordial ether, unless the latter is concealed in the concept of the primordial darkness.
It does, however, play an important role in the “Source of Wisdom.” This small book was always regarded by the kabbalists as one of the most enigmatic works of their literature. Baer of Mezritsch still boasted to his disciple Solomon of Luzk of having studied this book with the founder of Hasidism, Israel Baal-shem who, Baer said, explained it to him word by word.
It consists of two parts. The first is concerned largely with the divine name YHWH, the manner in which it was engendered by the processes of language-mysticism, its wondrous power, and the role of the primordial ether at the origin of all movement of language.
Here it seems that the idea of the spoken word becoming “inscribed” in the air, issuing from the mouth of the person uttering it, was applied to the primordial processes of the creative divine speech. In the second part successive attempts are made to develop a cosmogony.
The name of God—so the book begins—is the unity of the movement of language branching out from the primordial root. This movement grows out of the primordial ether, in the form of the thirteen pairs of opposites that are at the same time the thirteen middoth of divine government.”
Gershom Scholem, The Origins of the Kabbalah, pp. 331-2.