Merkavah mysticism, named for the divine chariot throne described in Ezekiel's opening vision, is the earliest well documented tradition of Jewish mysticism, flourishing from roughly the first centuries of the common era through the early medieval period. Its central religious practice was a visionary or ecstatic ascent, described in the surviving Hekhalot literature, palaces literature, as a journey through seven concentric heavenly palaces guarded by dangerous angelic gatekeepers, undertaken by an adept who had prepared through fasting, purity and the recitation of specific hymns and divine names, aiming to reach the seventh palace and behold the divine throne chariot itself.
The literature describes the ascent in vivid, sometimes frightening detail, including trials the traveler must pass and formulas needed to satisfy hostile angels, giving Merkavah texts a distinctive character closer to a technical manual for a dangerous journey than to philosophical or devotional writing. Rabbinic sources treated the subject with evident caution, restricting the study of Ezekiel's chariot vision to a small number of mature, qualified scholars, a restriction later echoed in the caution surrounding Kabbalistic study generally.