Chokmah, Wisdom, is the second sefirah and the first of the active emanations, the point at which the undifferentiated potential of Kether bursts into dynamic, outflowing force. In the imagery of the Tree of Life it heads the right-hand pillar, the Pillar of Mercy, and is the supernal masculine, the primordial father, Abba, whose creative impulse is received and given form by Binah, the supernal mother, across the abyss. Its divine name is Yah, a short form of the ineffable name of God.
Chokmah is wisdom not in the sense of accumulated knowledge but of the first flash of pure creative energy, the lightning-stroke of insight before it is shaped into understanding. As with all the sefirot, its place in the scheme is fixed by the Sefer Yetzirah and developed in the medieval Kabbalah of the Zohar; Chokmah and Binah together with Kether form the three supernal sefirot, set apart from the lower seven by the abyss, the gulf that separates the divine ideal from the created world below.
Sources The ZoharTraditionally attributed to Moses de Leon with Sefer Yetzirah: The Book of Creation in Theory and PracticeAryeh Kaplan