Adapted from the writings of Dayan Yitzhak Grossman February 29, 2024 AP News reports: The…
Initial Public Offering
Excerpted and adapted from a shiur by Rav Moshe Zev Granek
February 3, 2022
And they shall make for me a sanctuary, and I will dwell among them.
According to the Sefer Hachinuch (95), this pasuk includes the mitzvah of building the Bais Hamikdash in future generations. But he qualifies that the mitzvah applies only when the majority of Jews live in Eretz Yisrael. If so, the mitzvah would not apply yet, because less than half of the Jewish People currently does so.
Nevertheless, one opinion in the Gemara (Zvachim 108b) holds that korbanos may be offered even without a Bais Hamikdash. The Rambam explains that this is because the kedushah of the mekom hamikdash has never left. On the other hand, the Rambam also writes (Hil. Psulei Hamukdashin 3:22) that the mizbeiach must be built properly and placed in the proper location in order to be valid.
Despite the technical difficulties of constructing a kosher mizbeiach, some Acharonim, like the Yeshuos Malko, suggest that there is a mitzvah to build the mizbeiach so that korbanos can be offered. The She’eilas Dovid says this is not required, and the Gemara above merely permits korbanos to be offered but does not render it obligatory.
There may be another reason not to offer korbanos today: the Rambam’s statement (Melachim 11:1) that Mashiach will ultimately rebuild the Bais Hamikdash. Although we said that the mitzvah to build the Bais Hamikdash (and the mizbeiach) could apply when the majority of Jews reside in Eretz Yisrael, perhaps the mitzvah to offer korbanos takes effect only after the hashra’as haShechinah in the Bais Hamikdash, when Hashem expresses His desire for our offerings. This stage, according to the Rambam, will not occur until after Mashiach comes (see also Megillah 18a).
 As for the problem of identifying the mizbeiach’s correct location, these Acharonim note that strictly speaking, the mizbeiach need only be 5 by 5 amos (while in the Bayis Sheini, it was 32 by 32 amos), and the mizbeiach may be placed within approximately 20 amos of its proper spot.