EN SOF ("boundless"; "endless"):
Cabalistic term for the Deity prior to His self-manifestation in the production of the world, probably derived from Ibn Gabirol's term," the Endless One" (she-en lo tiklah). It was first used by Azriel ben Menahem, who, sharing the Neoplatonic view that God can have no desire, thought, word, or action, emphasized by it the negation of any attribute. The Zohar explains the term "En Sof" as follows: "Before He gave any shape to the world, before He produced any form, He was alone, without form and without resemblance to anything else. Who then can comprehend how He was before the Creation? Hence it is forbidden to lend Him any form or similitude, or even to call Him by His sacred name, or to indicate Him by a single letter or a single point. . . . But after He created the form of the Heavenly Man [ ], He used him as a chariot  wherein to descend, and He wishes to be called after His form, which is the sacred name '
In another passage the Zohar reduces the term to "En" (non-existent), because God so transcends human understanding as to be practically non-existent (ib. part iii. 288b). The three letters composing the word "En" () indicate the first three purely spiritual Sefirot ("Shoshan Sodot," 1b). Judah Ḥayyaṭ, in his commentary "Minḥat Yehudah" on the "Ma'areket Elahut," gives the following explanation of the term "En Sof": "Any name of God which is found in the Bible can not be applied to the Deity prior to His self-manifestation in the Creation, because the letters of those names were produced only after the emanation. . . . Moreover, a name implies a limitation in its bearer; and this is impossible in connection with the 'En Sof.'"
- Franck, La Kabbale, p. 136, Paris, 1889;
- Christian David Ginzburg, The Ḳabbalah, p. 105, London, 1865;
- Joël, Die Religionsphilosophie des Sohar, passim, Leipsic, 1849;
- Myer, Qabbalah, pp. 251 et seq., Philadelphia, 1888;
- Ehrenpreis, Die Entwickelung der Emanationslehre in der Kabbala des XIII. Jahrhunderts, p. 26, Frankfort-on-the-Main, 1895;
- Karppe, Etude sur les Origines et la Nature du Zohar, p. 344, Paris, 1901.