What is "Toras ha'Bayis"?
Radak: What was mentioned above.
What do we learn from "Al Rosh ha'Har"?
Radak: The Heichal will be on top of Har ha'Bayis.
Malbim: This distinguishes Bayis Shelishi from the previous Batim. (a) The mountain on which it is built will be "Nachon Yihyeh Har Beis Hashem b'Rosh Harim" (Yeshayah 2:2) ? at the head of all mountains 1 . (b) They thought to build Bayis Rishon in Ein Eitam, the highest place. They retracted, due to "u'Vein Keseifav Shachen" (between the shoulders, which is slightly below the head). Bayis Shelishi will be at the top of the mountain, to shows that it is most exalted. Also refer to 43:12:3:2.
Was it not so in Bayis Rishon and Sheni? Surely it was the most esteemed, and also the tallest ? "v'Kamta v'Alisa El ha'Makom" (Devarim 17:8) teaches that the Beis ha'Mikdash is higher than the rest of Eretz Yisrael, and Eretz Yisrael is higher than all other lands (Kidushin 69a)! Perhaps Eretz Yisrael was higher than inhabited places, but there were higher desolate mountains. In the future, those mountains will be lowered ? "v'Chol Har v'Giv'ah Yishpalu" (Yeshayah 40:4)! (PF)
What do we learn from "Kol Gevulo Saviv Kodesh Kodoshim"?
Radak: The entire border of Har [ha'Bayis] all around is Kodesh Kodoshim compared to Yerushalayim. All of Yerushalayim is Kodesh ? "v'Haysah Yerushalayim Kodesh" (Yo'el 4:17). The Har is Kodesh Kodoshim, In the Har itself, there are [more Kadosh places, e.g.] the Mikdash, Mizbe'ach and Dvir (Kodesh ha'Kodoshim).
Malbim: The entire border around Bayis Shelishi will be Kodesh Kodoshim. The city will be far away 1 , and 25,000 [square] Amos (Har ha'Bayis is 500 Amos by 500) in which the Mikdash is, it will be Kodesh and Terumas Hashem to Kohanim.
Malbim (7): It will be 45 Mil away.
Why does it repeat "Hine Zos Toras ha'Bayis"?
Radak: Above it was taught in detail, and in this verse, as a Klal.
Malbim: One who wants that it will be built, he must conduct like this Torah.
