Samizdat

Joseph Dan states that “A small library of about two dozen treatises reached us from the writings of Jewish esoterics in late antiquity dealing with these two subjects, the secret of creation and the secret of the divine realm, the merkavah. It is known as the “Hekhalot (celestial palaces or temples) and Merkavah” literature, because several of the treatises have these terms in their titles.”

“The most detailed work in this group is Seder Rabba de-Bereshit (The Extended Description of Genesis). The second main subject in this small library is magic.”

Dan refers to the “most elaborate ancient Jewish directory for magical formulas,” the Harba de-Moshe (The Sword of Moses), which includes “several hundred magical incantations and procedures …” from “magical remedies to love potions to walking on water.”

Magic is prominently addressed in the Sefer ha-Razim (The Book of Secrets). The third main subject is the description of the chariot in Ezekiel and other biblical sections describing the abode of God. The texts include detailed lists of angels, naming them and their functions, as well as discussions of the secret names of God and the archangels.

The fourth subject “describes an active procedure by which a person can ascend to the divine realms and reach the highest level, and even “face God in his glory.” The process of ascension is termed “descent to the chariot,” and the sages who accomplish it are called yordey ha-merkavah (the descenders to the chariot). These are first-person accounts attributed to Rabbi Akibah and Rabbi Ishmael. These sages overcame many dangers to “join with the angels in the celestial rituals of praise to God.”

The Shiur Komah (The Measurement of the Height) relates a list of God’s limbs, beard, forehead, eyes and irises, designated by obscure, strange, unpronounceable names, measured in terms of miles, feet and fingers. The basic measurement used is the length of the whole universe (derived from Isaiah 40:12), yet each divine limb is trillions of times longer. It is the source of the sefirot, the kabbalistic system of divine attributes. 

–Joseph Dan, Kabbalah: A Very Short Introduction, 2006, pp. 13-15.