When did Zerubavel found the Bayis?
Rashi: From the beginning to the end, in the days of the first Koresh (Ezra 3:8-11).
Malbim: Now he laid only the foundation for the Bayis that will be in the future. Bayis Sheni that they build now, it is not finished and complete. It lacked five matters 1 [that were in Bayis Rishon - Yuma 21b] and it was destined to be destroyed. It is merely the foundation and beginning of the building that will be in the end of days.
Yuma 21b: They are the Aron, Urim v'Tumim, fire [from Shamayim], Shechinah and Ru'ach ha'Kodesh.
What is the meaning of "v'Yadav Tevatzanah"?
Rashi: His hands will finish it now. Tevatzanah is an expression of finishing, like "Ki Yevatza Hashem Es Kol Ma'asehu" (Yeshayah 10:12).
Malbim: In the future, his hands will finish the building [via building Bayis Shelishi]. Chazal said, this is why they built it like Binyan Shlomo and like Binyan Yechezkel in the future, for it is in the middle between them. It is the end of Bayis Rishon and the foundation of the Acharon.
What do we learn from "v'Yadata Ki Hashem Tzevakos Shelachani Aleichem"?
Malbim: [When Bayis Shelishi will be built], you will know that Hashem sent me to you.
