ייִדישער מחשבֿה אויף יחזקאל 40:34

The Future Beis HaMikdash will have 8 steps leading to the Courtyard of the Israelites instead of 15 steps. This means that the Courtyard of the Israelites will only be 10 cubits above the Temple Mount, and the Ulam will only be 18 1/2 cubits above the Temple Mount. Thus, the entire structure will be 3 1/2 cubits lower, making it unnecessary to reduce the height of the eastern wall of the Future Beis HaMikdash.³²The Kohen Gadol would burn the red heifer on the Mount of Olives (see the accompanying diagram). He is required to see the entrance to the Sanctuary when doing so. Tosafos Yom Tov is discussing whether it is necessary to lower the wall around the Outer Courtyard to enable him to do so. Hence, we can posit that the wall around the Temple Mount was not low to enable the kohen burning the red heifer to see the entrance to the Sanctuary, but for another reason, as explained by Rav Yitzchak Abarbanel. According to this approach, there is no difference between the eastern wall and the walls on the other sides.