Why does it say "Asuyah" (feminine singular)? The subject is "Keruvim v'Simorim"!
Radak: It refers to the form. It is as if it says va'Asuyah Tzuras Keruvim?
Were they "El (towards) Dalsos ha'Heichal"?
Radak: [The forms of Keruvim and date trees] were on them. El is like Al. There are many verses like this.
Malbim: This clarifies the previous verse. "U'Shetayim Delasos la'Delasos?" was only for the doors of the Heichal, but not for Pesach Kodesh ha'Kodoshim, which was only two Amos wide 1 .
I.e. from east to west. The opening was 20 Amos from north to south, just like Pesach ha'Heichal; this is its length. (PF)
What does "Aleihen" refer to?
Radak: To the doors of the Heichal, like it says after this. We find a pronoun, and afterwards the noun for which it stands ? "va'Tir'ehu Es ha'Yeled" (Shemos 2:6) and similar verses.
What are "Kiros"?
Rashi: This is [beams,] like "Koros Bateinu" (Shir ha'Shirim 1:17).
Malbim: These are walls. We learned above (18-19) that the forms of Keruvim and date trees] were on the walls.
What is "v'Av Etz Al Pnei ha'Ulam [meha'Chutz]"?
Rashi: Cedar poles were fixed from the wall of the Heichal to the wall of the Ulam, lest Yeva'etu (the walls fall, due to their height ? Midos 3:8). The verse says that thick wooden beams [go from the wall of the Heichal] to the Ulam from the outside [the Ulam ? Radak].
Radak: It is called Av even when it is not Samuch, e.g. "v'Av El Pneihem" (Melachim I, 7:6). Chazal called it Marish (a beam), e.g. a Marish built into a building (Bava Kama 67a). It was put into the wall of the Ulam from outside, towards the Mizbe'ach. And so it was in Bayis Rishon "Kerusos Arazim" (Melachim I, 6:36). Chazal said that they were built into the walls.
Malbim: Even though the Ulam did not have a lintel above, there were thick beams on the opening, like a roof, like it says in Midos (3:7) 'there were five beams of gall-wood over Pesach ha'Ulam. They extended past the opening (which was 20 Amos long); the top beam was 30 Amos long.