Rashi: It does not specify here the height of the Bayis. In Midos (4:6) it says that the height was 100 Amos [in Bayis Sheni].

Vilna Gaon: I saw that Kodesh ha'Kodoshim ¹ is taller than the cells around it.

Malbim: Until now, he did not pay attention to heights. When he saw the ramp surround the Bayis several times, he was aroused to its height. For every 300 Amos of ramp, the Bayis was 100 Amos tall ² .

Malbim: This implies that it was much taller than previous buildings. Bayis Sheni was 100 Amos tall; perhaps this was 200 ¹ . The ramp around the Bayis was not only to enter the higher cells ? it was also to ascend to the Bayis' roof or Aliyah. A ramp ascending to [100 or] 200 Amos would be [300 or] 600 Amos long ² . It would surround the Bayis a few times. Therefore, one could not ascend via Lulim, like in Bayis Rishon.

Rashi: The foundation of the cells was a full Kaneh. Vilna Gaon ? this was until the height of six Amos.

Radak: Aleph, Hei, Vov and Yud are interchangeable.

Rashi citing Targum Yonasan: The foundation of the wall in the ground was six Amos wide, but above the ground it was five Amos wide, like the coming verse says.

Radak #1, Vilna Gaon: Atzilah is big (they were big Amos). "V'El Atzilei Bnei Yisrael" (Shemos 24:11) is great [Yisraelim].

Radak #2: Atzilah is like "mi'Tachas Atzilus Yadecha" (Yirmeyah 38:12), the underarm. Other Amos are from the end of the index finger until the elbow; these are until the underarm.

Malbim: The Mikdash was on a mountain. One who approached the Mikdash needed to ascend steps. He saw that next to the cells, the foundation was elevated six Amos; it stick out, and was visible from the outside. The Yesod was six wide ? it was Atzul (separated) from the cell wall, which was only five wide. In Bayis Rishon, they leveled the ground before beginning to build the Yesod. Here they leveled the ground after building the Yesod, and the Yesod was revealed ? six Amos ¹ .