Atziluth or Atzilut (also Olam Atsiluth, עוֹלָם אֲצִילוּת, literally “the World of Emanation”), is the highest of the four worlds in which the Kabbalistic Tree of Life is “placed”.
It is known as the World of Emanations, and each of the Sephiroth of this world is associated with a GOD’s Name.

Atziluth is the realm of pure divinity, the highest of the entire tree of four worlds in total. They are described one above the other, in symbolic form by a diagram called Jacob’s Ladder. Then it is taught that the Tree of Life can be divided into four horizontal sections, each representing one of the four worlds.

The realm of Atziluth is thus related to the three upper Sephirot of the Tree of Life; these three spheres (Kether, Chokmah and Binah) are considered to be entirely spiritual in nature and are separated from the rest of the tree by a region of reality called the Abyss.

The word is derived from “atzal” (from the root אצל meaning “to set aside, reserve or issue.”) in reference to Ezekiel 42, 6 and in this sense was taken in the Kabbalah from the Meḳor Ḥayyim (The Source of Life) of Solomon ibn Gabirol, much used by Kabbalists.