In an article in Hebrew that I have only partially published on the internet, I raise the possibility that maybe and I stress maybe, Radbaz believed, that the Temple Mount’s Eastern Wall was beyond the current Eastern Wall that we see today. See Pe’at Hashulchan, Hilchot Eretz Yisrael, chapter 3, Beit Yisrael 26 by Rabbi Yisrael of Shklov (a disciple of the Vilna Gaon) for more about this possibility. What I wrote in the caption to the picture is the mainstream view.
והיה הטוב ההוא AND IT SHALL BE THAT WHAT GOODNESS [THE LORD SHALL DO UNTO US, THE SAME WILL WE DO UNTO THEE] — What good did they actually bestow upon him (i.e. when did they redeem their promise)? They (our Sages) say: When the Israelites were parcelling out the Land the most fertile part of Jericho proved to extend over an area of 500 by 500 cubits; they left it unparcelled and said: He in whose portion of land the Sanctuary will be built shall take it as a substitute for giving up the land upon which the Temple was built. In the meantime, however, they gave it to the children of Jethro — to Jonadab the son of Rechab, [as it is said, (Judges 1:16) “And the children of the Kenite, Moses’ father-in-law, went up out of the city of the palm tree” (which is identical with Jericho; cf. Deuteronomy 34:3)] (Sifrei Bamidbar 81).
post by: Shlomo Scheinman
Appendix: A Hint for the Scholars.
The map below showing the Temple Mount at the time of Radbaz might help solve a major difficulty regarding what Radbaz meant in his halachic Teshuva Vol. 2, Chapter 691 regarding ascent to the Temple Mount