It may be suggested that the Temple of the future ("it will be revealed and come from heaven already built and perfected") will first be revealed in the place "That the Temple traveled and settled there" in the time of exile ("The House of our Rebbe in Bavel"); from there it will be transported to its place in Yerushalayim.
...Perhaps it can be said that this is alluded to in the Rambam's choice of words (in Hilchos Melech HaMoshiach) "And build the Temple in its place." For apparently [there is a question]: what is the need to inform us here that the building of the Temple will be in its place? On the other hand, why isn't the place specified: "And build the Temple in Yerushalayim?" [It must be] that "in its place" alludes as well to the place of the king Moshiach in the time of exile (before [the status of] "behold he is certainly Moshiach"). Therefore, while he is still in exile (for there he sits and waits and anxiously looks forward to redeeming the Jewish people, and the Divine Presence with them in exile) the king Moshiach builds a Temple (in microcosm). This is an illustration and example of the Temple in Yerushalayim (like "the synagogue of He slipped and settled," "that the Temple traveled and settled there.").
Settling as Preparation for the Future Temple
[This settling serves] as a preparation for the future Temple, which will be revealed there first, and from there return (with G-d and the Jewish people) to Yerushalayim.
...Perhaps it can be said that the statement in the Midrash, that "at the time when the king Moshiach comes, he will stand on the roof of the Beis HaMikdash [Temple] and announce to the Jewish people, saying, Humble ones, the time for your Redemption has arrived," refers to the roof of the Beis HaMikdash which is the Temple in microcosm outside the land, which takes the place of the Temple in Yerushalayim ("The Temple traveled and settled there"). [This may be said] because after the future Temple is revealed and descends to the earth below, there is no need to announce to the Jewish people that "the time for your Redemption has arrived."
Application to "The House of our Rebbe in Bavel"
...The above can be applied to "The House of our Rebbe in Bavel" of our generation, the house (the synagogue and study hall) of my sainted father-in-law, the leader of our generation:
...In this generation, the last generation of exile and the first generation of Redemption, "our actions and Divine service during the time of exile" to make the lands of the nations into the land of Israel even in the lowest possible place, that is, the lower hemisphere (where the Torah was not given) has been concluded and completed. Through the elevation of the lowest possible place all the other lands of the nations are also elevated.
This [objective] is achieved through "Beis Rabbeinu" [Our Rebbe's House] in the lower hemisphere, from which light goes out to all the world, to make the whole world (until the furthermost corner of the world) into the land of Israel. This is the concept that "In the future the land of Israel will extend into all the lands," and "In the future, Yerushalayim will extend over all the land of Israel." For then there will be established a connection between all the synagogues and study halls throughout the entire world and the Beis HaMikdash. [This will occur] in the true and complete Redemption through our righteous Moshiach, the leader of the generation, who is the Moshiach (the Redeemer of Israel) of the generation. Further, and this is also essential, he is the leader of the Torah of Chassidus, since through the spreading outward ("when your wellsprings spread forth," until there is nothing beyond, to all corners of the world) is achieved the coming of the king Moshiach.
The Greatness of "Beis Rabbeinu"
Therefore the greatness of "Beis Rabbeinu" can be understood. It is the essential "Temple in microcosm" of the final exile, "that the Temple traveled and settled there." Therefore, it is the actual place of the Temple of the future; not only that, but the future Temple will be revealed there, and from there return to Yerushalayim (as mentioned above).
Allusions in the Name "Beis Rabbeinu"
It may be added, that this concept is also alluded to in the name of "Beis Rabbeinu" in our generation:
"Rabbeinu" [our Rebbe] - His two names alluded to the Redemption: His first name - Yosef - "And it shall come to pass that on that day, the L-rd shall continue to apply [yoseef] His hand a second time to acquire the rest of His people that will remain from Assyria and Egypt, etc. and from the islands of the sea, etc, and He shall gather [Asaf] the lost of Israel and the scattered ones of Judah He shall gather from the four corners of the earth."
His second name - Yitzchak - refers to the laughter and rejoicing that will be complete in the future Redemption, and which will be completed through our righteous Moshiach. Thus it is written, "Then our mouths will be filled with laughter [S'chok]. It specifies "then," in the future, when they will say to Yitzchak (specifically), "Because you are our father."
And Beis (Rabbeinu) [The House of our Rebbe] - its number is seven hundred seventy. The name by which "Beis Rabbeinu" is called by all Jews has been universally accepted to be this number, "770." This number in Gematria is "Paratzta," derived from "You shall spread out [U'Faratzta] west and east and north and south." This indicates that from this house light will go forth to all four corners of the world, in a manner of breaking through barriers, so that all four corners of the world will be elevated to the status of the land of Israel. (In the future the land of Israel will extend to all the lands.) This means in particular that all the synagogues and study halls throughout the world will be established in the land of Israel and connected to the Beis HaMikdash in the true and complete Redemption through our righteous Moshiach. For about him it says, "You have broken barriers for yourself," which our Sages of blessed memory explain as follows: "This is Moshiach, about whom it is said, "The breaker is come up before them."
The Completeness of the Number Seven
...In the completeness of the number seven (seven hundred and seventy) can also be found an allusion to the completeness of the Divine service of our Rebbe during his complete lifetime of seven decades, seventy years (5640-5710). His Divine service was concluded and completed in the lower hemisphere in the seventh decade (from the house whose number is seven hundred seventy). [This completeness] includes as well the extension of his Divine service in the years afterwards, through the seventh generation - "all sevenths are beloved." Through this [extension] is accomplished the completion of our actions and Divine service during the time of exile in all seven continents of the world. Immediately and imminently "the L-rd shall continue to apply [yoseef] His hand a second time, etc., and He shall gather [Asaf] the lost of Israel, etc." In this way, "You have broken (in Gematria, seven hundred and seventy) barriers for yourself," "The breaker is come up before them."
Recent Emphasis and Expansion
All this receives added emphasis in this last period: The Divine service of spreading Torah and Judaism and the wellsprings outward from "Beis Rabbeinu" ("770") has continued and expanded with greater vigor and greater strength, even after (the last ten years of) his life in this world, for more than forty years (5710-5750). It has done so in a way that "G-d has given you a heart to know and eyes to see and ears to hear." Thus we find that "Beis Rabbeinu" ("770") is a "fortress," "the mount that all mouths turn to," for more than a Yovel of years (5700-5750) - "Forever."
[That Beis Rabbeinu is a "fortress"] receives further emphasis when we see with our own eyes the many Jewish people, and the increasing numbers of them, that come to "Beis Rabbeinu," with greater vigor and greater strength, - "in the multitude of people is the splendor of the king" (which includes also "Who are the kings? the rabbis," and specifically the leader (king) of the generation). [The increase] has made it necessary to enlarge and expand "Beis Rabbeinu" further. The enlargement and expansion must be in a way that breaks through barriers, "Paratzta" (770 in Gematria), as if constructing a new building.
The Merit of Building "Beis Rabbeinu Sh'b'Bavel"
According to what was said previously concerning the pre-eminence of "Beis Rabbeinu Sh'b'Bavel" - that "the Temple traveled and settled there," and "this is the place of the actual Temple in the future," so that there the future Temple will be revealed and from there return to Yerushalayim - the great merit each and every Jew has in becoming a partner, physically and monetarily (and all who increase are praiseworthy) in building "Beis Rabbeinu Sh'b'Bavel" is obvious. And this is like a preparation for the actual descent and revelation of the future Temple, imminently and immediately.
(Pamphlet concerning "Mikdash M'at Zeh Beis Rabbeinu Sh'B'Bavel" - Sefer HaSichos 5752, p, 465)
