Hekhalot literature (sometimes transliterated as Heichalot), from the Hebrew word for "Palaces," relates to visions of ascents into heavenly palaces.
Hekhalot literature is a genre of Jewish esoteric and revelatory texts produced some time between late antiquity — some believe from Talmudic times or earlier — to the Early Middle Ages.
Many motifs of later Kabbalah are based on the Hekhalot texts, and Hekhalot literature itself is based upon earlier sources, including traditions about heavenly ascents of Enoch found among the Dead Sea scrolls and the Hebrew Bible pseudepigrapha.
[2] Some of the Hekhalot texts are:[3] Other similar texts are:[4] Hekhalot literature is post-rabbinical, and not a literature of the rabbis, but since it seeks to stand in continuity with the Rabbinic literature, it is often pseudepigraphical.
[5] Hekhalot has examples of early alternate history texts.