There are two levels of "nothing," absolute nothing and relative nothing, and two levels of "something," intangible something and tangible something.
Absolute nothing is the awareness that besides the absolute existence of God all is naught and that God's absolute existence is absolutely incomprehensible; relative nothing is the state of nothing that precedes creation ex-nihilo; intangible something is the aspect of reality we can't directly experience; tangible something is the aspect of reality we can directly experience.
The Hebrew terms for "absolute nothing," "relative nothing," "intangible something," and "tangible something" (as they appear in the classic texts of Kabbalah and Chasidut, when the concepts are meant to be distinguished one from the other) are efes (אפס), ayin (אין), yesh (יש), and mamash (ממש), respectively.
The two levels of nothing are alluded to in the Divine Name that God revealed to Moses before the Exodus from Egypt, "I shall be that which I shall be" (אהיה אשר אהיה). "I shall be" implies that as yet there is no defined state of being, that being is still potential, not actual. There are two states of "potential," "non-existent potential" (העלם שאינו במציאות) and "existent potential" (העלם שישנו במציאות). They correspond to the two states of nothing (absolute nothing and relative nothing, respectively) and to the two times "I shall be" in the Name that God revealed to Moses (before the Exodus, the Jewish people themselves were in a state of potential, the potential to become God's chosen people).
The intangible something corresponds to God's essential Name (relating to His attribute of mercy), Havayah ('הוי), which literally means "being" (implying that being has become actualized, that it can be known). Jacob, after awaking from his dream of the ladder (symbolizing prayer) reaching from earth to heaven, said "There is Havayah ['יש הוי] in this place," explicitly stating that Havayah is "something" (יש).
The tangible something corresponds to God's Name Elokim (אלהים), the Name that appears exclusively in the original account of creation (whose gematria is equal to that of "nature" [הטבע], reality as we experience it).
|Degree of Being||Sefirah||Name of God|
|Absolute nothing (אפס)||Crown||אהיה||(Non-existent potential)|
|Relative nothing (אין)||Wisdom||אהיה||(Existent potential)|
|Intangible something (יש)||Understanding||'הוי|
|Tangible something (ממש)||Kingdom||אלהים|
"I shall be that which I shall be" = 543; Havayah = 26; Elokim = 86. Together they equal 655 = The Holy One Blessed Be He (הקדוש ברוך הוא), the all-inclusive connotation of God used by the sages.
Adding 655 to the four basic terms that correspond to the Names of God, absolute nothing (efes, 141), relative nothing (ayin, 61), intangible something (yesh, 310), and tangible something (mamash, 380) gives 1547 = 7 times 13 times 17 = Havayah (26) plus all 27 possible fillings of Havayah (which total 1521, 39 – "Havayah is one" [הוי' אחד] – squared). From this we conclude that all is Havayah (and "Havayah is one").