Regarding the rebuilding of the Third Temple envisioned in the prophecies of Yechezkel (Yechezkel chs. 40-48), there are two opinions: One view maintains that the future Beis HaMikdash will be built by the Holy One, blessed is He, Himself (Shemos Rabbah 15:1; Tanchuma, Ki Tissa 13). Similarly, the greatest of the classic commentators, Rashi, writes that the future Temple which we eagerly await, stands in the heavens fully built and exquisitely decoareted and from there it will descend. This is the meaning of the verse (Shemos 16:17), “The Sanctuary, O God, which Your hands have established” (commentary to Sukkah 41a). The Gemra (Rhos HaShanah 301) also endorses this view: “The future Temple is in the hands of heaven.” (Rabbi Shalom Dov Seinberg, The Third Beis HaMikdash: The Third Temple According to the Prophecy of Yechezkel Following Rashi and Tasofos Yom Tov [trans. Rabbi Moshe Leib Miller; Jerusalem: Moznaim Publications, 1992] [i])
