"Tzimtzum": God "Contracted" Himself?
Reader: I am reader who appreciates your work and who has been learning from your site for many years.
Question: Can you offer a reasonable explanation for what the Rav wrote (Rosh Hashana Machzor, pages 350-51), based on the Pasuk of "Gavaso Godla Olam Meyhachil" – "His grandeur is more than the world can contain":
"The Kabbalists, especially the Ari HaKadosh and later the first Lebavitcher Rebbe, discuss how the creation of the world is based on the concept of Tzimtzum, or contraction. God, the Infinite, the Ein-sof, contracted Himself in order to allow the existence of the world. Otherwise, a finite world could not coexist with the Infinite. The Midrash (Shemos Rabbah 34:1) illustrates the concept of Tzimtzum by relating the following; At the time Hashem instructed Moses to build Him a Mishkan, Moses was astonished, noting that Hashem's glory fills the upper and lower worlds; how would it be possible to build a Mishkan for His Presence? Moreover, he foresaw that King Solomon, after building the Temple, which was much larger than the Mishkan, similarly wondered how even that larger structure could contain Hashem's Presence (see 1 Kings 8:27).
Hashem responded, "I will descend and contract (Tzimtzum) My Divine Presence to fit within an area of one cubit (on top of the Ark between the two cherubs)." If Israel fulfills its mission as the chosen people, then God promises that He will perform this miracle of Tzimtzum (Derashot HaRav, pp 23-24).
Mystics mistakenly assert that man must strive to remove himself from his physical being, for how can the physical-biological stand within a holy place? Yet, because holiness is created by man, it is he who brings the glory of God into this world. A sacrifice is consecrated via man's designation. The Land of Israel became holy through man's conquest. By making a sanctuary for God, man sanctifies space, and through this creation of holiness, infinity contracts itself. Judaism has given the world the secret of Tzimtzum, contraction of the infinite within the finite, the transcendent within the concrete, the Divine within the realm of reality (Halachic Man, 99 47-48).
Rabbi: You quote, "God, the Infinite, the Ein-sof, contracted (tzimtzum) Himself in order to allow the existence of the world. Otherwise, a finite world could not coexist with the Infinite."
We must be loyal to God's words, "I am God, I do not change” (Malachi, 3:6) So any idea of "contraction" (tzimtzum) must not be applied to God's "existence", but rather, is either 1) metaphoric, or 2) refers to God's created, manifestation.
But that quote as is, is very misleading, and read simply, it suggests the heretical notion that the world and God share something common. In truth, the world doesn't exist "with" God as that quote states. Nor does the world have any affect on God. That too is heretical. These cannot be the words of the Rav, but an editor's addition. But there might be a way to talk about "tzimtzum" in another sense...
You also quote Medrash Rabbah, "Moses was astonished"..."how would it be possible to build a Mishkan for His Presence?" Of course, Medrash Rabbah knows that Moshe did not view God spatially! Moshe's concern was how an Earthly, manmade structure, which is far less lofty than the heavens, can accurately and fully communicate God's glory to man. That is, if the heavens compromise God's greatness (finite heavens cannot contain God's infinite marvels) "certainly this house that I built" cannot relate God's greatness. Shlomo Hamelech says this openly (Kings I, 8:27) with emphasis on "that I built". That is, an edifice (art) is far less accurate in telling of God's greatness, than are the heavens (nature).
And you also quote the Rav, "By making a sanctuary for God, man sanctifies space, and through this creation of holiness, infinity contracts itself. Judaism has given the world the secret of Tzimtzum, contraction of the infinite within the finite, the transcendent within the concrete, the Divine within the realm of reality".
To my understanding, this means that through Torah adherence and sharing its ideas with others through our actions and objects of mitzvah, the Jew publicizes the infinite God in our finite world.
I do not feel Moshe and Shlomo were "concerned" about how truths of God would be successfully transmitted through the physical world, since they were the wisest men and knew Torah was true. Thus, God's command of building a Temple must contain truths. Radak teaches that Shlomo made his statement publicly, as he wished to halt a false notion before it laid roots. As he had just completed building the Temple, he was justifiably concerned that the nation might attribute some "presence" of God Himself "IN" Temple. Therefore Shlomo opens that verse with a rhetorical question, "Can God actually dwell on Earth?!" He is dissuading the nation from any false beliefs. The nation must have been overwhelmed and enamored by this gold and silver structure; the cherubim, the menora and all the vessels. Shlomo was correct to head off dangerous notions right away upon the Temple's completion. Radak explains that the temple was meant to be a metaphor for God's will and honor. But God has no relationship with physical space, even His Temple.
God does not exist "with" the world, and thus, there is no need for Hims to "make room for it" by contracting Himself. This heretical notion exists, since many individuals cannot view an existence that is outside of their senses. They feel everything has location, even God. From this first error, they make a second, suggesting God had to make room for the universe.
 The Talmud teaches that the instinctual drive is most powerful when tied to religious practice.
 Kings I, 8:27