Nonsense

It's nonsense but it's Jewish nonsense, the study of anything Jewish even nonsense, is worthwhile. ~ Orthodox scholar on mysticism

Ein Sof, (Hebrew: אין סוף‬), in Kabbalah, is understood as God prior to his self-manifestation in the production of any spiritual realm, probably derived from Ibn Gabirol's term, "the Endless One" (she-en lo tiklah). Ein Sof may be translated as "unending", "(there is) no end", or infinity. It was first used by Azriel, who, sharing the Neoplatonic belief that God can have no desire, thought, word, or action, emphasized by it the negation of any attribute. Of the Ein Sof, nothing ("Ein") can be grasped ("Sof"-limitation). It is the origin of the Ohr Ein Sof, the "Infinite Light" of paradoxical divine self-knowledge, nullified within the Ein Sof prior to creation. In Lurianic Kabbalah, the first act of creation, the Tzimtzum self "withdrawal" of God to create an "empty space", takes place from there. In Hasidism, the Tzimtzum is only the illusionary concealment of the Ohr Ein Sof, giving rise to monistic panentheism. Consequently, Hasidism focuses on the Atzmus divine essence, rooted higher within the Godhead than the Ein Sof, which is limited to infinitude, and reflected in the essence (Etzem) of the Torah and the soul.

The Zohar explains the term "Ein 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 "YHWH".

In other words, "Ein Sof" signifies "the nameless being". In another passage the Zohar reduces the term to "Ein" (non-existent), because God so transcends human understanding as to be practically non-existent.

In addition to the Sefer Yetzirah and the Zohar, other well-known explications of the relation between Ein Sof and all other realities and levels of reality have been formulated by the Jewish mystical thinkers of the Middle Ages, such as Isaac the Blind and Azriel. Judah Ḥayyaṭ, in his commentary Minḥat Yehudah on the Ma'areket Elahut, gives the following explanation of the term "Ein 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 "Ein Sof"

According to Gershom Scholem, the Ein Sof is the emanator of the ten sefirot. Sefirot are energy emanations found on the Kabbalistic Tree of Life. Ein Sof, the Atik Yomin ("Ancient of Days"), emanates the sefirot into the cosmic womb of the Ayin in a manner that results in the created universe. The three letters composing the word "Ayin" (אי״ן), indicate the first three purely intellectual sefirot, which precede any emotion or action.."
~ Wikipedia