The appreciation of God’s unknowable but eternal existence is expressed by the kabbalists in the term Ein-Sof (the "Infinite”). In startling contrast, the mystics posit the first manifestation of the Ein-Sof as Ayin ("Nothingness”). Although initially confusing, this "nothingness” describes the barrier that confronts our human intellects when they reach out to comprehend Divinity. We are limited in our ability to comprehend God’s manifestation, and therefore "nothingness” is the appropriate mirror to the concept of "infiniteness.”
This leads to the following deduction: God, Who is called Ein-Sof in respect of Himself, is called Ayin in respect of His first revelation. It is the understanding of this order of Creation that turns the classical doctrine of creatio ex nihilo ("creation from nothing”) on its head. In the mystical view this ancient Latin formula is interpreted as creation from within God Himself. One of the great medieval rabbinic commentators, Nachmanides, a renowned kabbalist, addresses the topic of creatio ex nihilo in its literal sense, that is, as the free creation of the primeval matter from which everything was made. Simultaneously, Nachmanides employs the term Ayin in his commentary on the Genesis Creation narrative, in order to underline the mystical meaning of the text, which avers that all things emerge from the absolute nothingness of God.
Another theory suggests that there exist above all the powers of Divine emanation "three hidden lights” which have no beginning, but serve as "the root of all roots.” At the same time, as in the case of the Ayin ("nothingness”), they are beyond our intellectual grasp. The three lights begin with one primeval inner light that spreads through the hidden root, kindling the two other lights. Together these three lights constitute one essence and one root that is "infinitely hidden.” What is formed then is a kabbalistic trinity that precedes the emanation of the ten Sefirot ("Emanations”). The three lights are called "Splendors” and serve as the roots of the three uppermost emanations.
This theory of the "three hidden lights” is believed to have emerged from the need to make the ten Emanations conform with the thirteen Attributes of God. That Christians later found these "big three” as an allusion to their own doctrine of the trinity is not surprising, although nothing here suggests any relationship to the persons and personalization of that famous non-Jewish configuration. In the mystical context, these "Splendors” found a niche between the Ein-Sof and the Sefirot.