In light of the sources adduced supra from the Torah, the Prophets, as well as the Talmud, the Midrash and the Zohar, it is evident that the precept of rebuilding the Temple is both obligatory and lasting.
It is, therefore, not surprising to find that Maimonides states in Sefer HaMitzvot (Book of Precepts) that the precept of rebuilding the Temple is lasting.
This, too, is what he wrote at the opening of Hilkhot Beit HaBehira (Laws of the Temple): "It is a positive precept to build a House for Hashem . . . as it is written: And they shall build Me a Temple . . . A 'Holy Place' and a 'Holy of Holies' are to be made in it . . . and vessels are to be made in the Temple . . . and flooring is to be laid, etc." In this way Maimonides lists in eighteen chapters the details of the act of building a Temple, according to tractate Middot and other Talmudic tractates. Maimonides makes no mention whatever, neither in his books of Halakha nor in his philosophical works, of the possibility of a Temple descending from Heaven.
Rashi mentions the Concept of a 'Heaven-sent Temple' as a Solution to a Problem of Interpretation of an Unusual Topic.
As noted above, Rashi's opinion in his commentary to the Torah, to the writings of the Prophets and to the Talmud is that the Temple will be rebuilt by Man. Indeed, in his commentary to tractate Sukka (41a), where the possibility of the Third Temple being built just before the festival of Passover is considered, Rashi does make mention of a 'Heaven-sent Temple' -- but in a specific context.
One of the possibilities considered by the Talmud is that the Temple will be rebuilt on the first day of Passover. In conclusion, this possibility is rejected. Yet Rashi, as a commentator, saw fit to solve the problem of how the Temple could possibly be built on the first day of Passover (it should be noted that other Rishonim, such as HaMeiri, explain that it could happen as the result of a mistaken court decision allowing the builders to finish their work after the onset of the festival). The solution that Rashi suggests to explain the opinion of the Talmudic sage is the following: "The future Temple we await, built and complete, will appear and come from Heaven." Rashi writes this to explain the development of the Talmudic discussion, though in conclusion the possibility is rejected, and the need for such a solution, based as it is on Aggada, no longer exists.
It is thus surprising that a number of authorities of this generation have seen fit to turn this excerpt from Rashi into the basis of their halakhic opinions concerning the invalidation of the positive precept of building the Temple in our time.
Believing in a Temple descending from Heaven and attributing this to Rashi is repaying good with evil.
Anyone studying that topic of discussion will note just how Rashi writes explicitly that the Third Temple will be built by human beings. As he wrote at the beginning of the topic: When will the work be completed? it was clear to Rashi that the labor of constructing the Third Temple will be performed by the Jewish people. And if he states that "the Temple will appear and come from Heaven" as a possible solution to the problem posed in the Talmud, did he declare that this is "Rashi's opinion"? Did he write anywhere that the precept of constructing the Third Temple has become invalid? It was this sort of matter the prophet Jeremiah was referring to when he stated (19:5): that which I did not command nor did I say nor did it even occur to me!
Maimonides has already written in the prelude to his book, Guide to the Perplexed, that he requests of all his readers that they interpret his statements so as to correspond to his intention in writing. For if one was to interpret his writings contrary to his intention, he would be doing harm and returning evil to the writer instead of good. It would seem that to frame these words by Rashi and call them "Rashi's opinion", contrary to what he expressed in straight-forward, logical fashion in his commentary, would be a showing of ingratitude to this great Torah commentator.
