Sefer ha-Bahir, which appeared in Provence in the late twelfth century, is a collection of short midrashic sayings and parables. It is the first text to present the sefirot as aspects of God and to speak of the feminine divine and of transmigration, and it marks the beginning of medieval Kabbalah.
Bahir
The Book of Brightness: an early kabbalistic text, among the first to describe the sefirot as divine powers.
Also: Sefer ha-Bahir