What were the Keruvim?
Rashi, Ramban, Rashbam #2 (both citing Sukah, 5b) and Seforno: Angels 1 with the face of a child. 2
Rashbam #1: A large species of bird, as in Yechezkel, 28:14.
R. Bachye: They are angels. 3 We are commanded to believe that angels exist, for they bestow Chochmah and prophecy through Hashem's command.
Ramban: They were the same angels that Yechezkel saw in his vision of the Merkavah, which he specifically refers to as 'Keruvim' - in Yechezkel, 10:20. See also Ramban, who hints according to Kabalah why the Keruvim faced each other and why they were 'beaten'.
As a matter of fact, the word "Keruvim" really reads 'ke'Ravya', like children (Ramban) See also Sifsei Chachamim and Ba'al ha'Turim. Because on Bavel, they call children 'Ravya' (Chagigah, 13b.
Why does the Torah write "Shenayim Keruvim " and not "Sh'nei"?
R. Bachye: Whenever the Torah writes "Sh'nei" it means that they are exactly the same, 1 which is not the case here since one of them had the face of a male, the other, of a female. 2 And it is to indicate that they were to be formed as a couple (and not as two individuals) that the Torah writes "Shenayim". 3
Seeing as the minimum of plural is two anyway. See for example, Ki Sisa, Sh'mos, 31:18 and Pinchas Bamidbar, 28:9.
See R. Bachye.
See Torah Temimah, note 23, from DH 've'Ayein', who queries this and elaborates.
What is the meaning of "Mikshah"?
Rashi, Rashbam, Targum Onkelos and Targum Yonasan: It means that the Keruvim were beaten (with a hammer - Rashbam) out of the same lump of gold as the Kapores, 1 and not manufactured independently and soldered on to it later.
As the Torah explains later - in Pasuk 19 (Rashi there).
How will we reconcile the current Pasuk with the Pasuk in Vayikra, 1:1, which implies that Hashem spoke to Moshe from the Ohel Mo'ed - outside the Paroches?
Rashi (in Nasi, Bamidbar, 7:89): Hashem's Voice came down from Heaven to between the two Keruvim, from where it traveled to the Ohel Mo'ed, which is where Moshe heard it.
Rashi (in 20:20) writes that it is forbidden to make four Keruvim instead of two. But Shlomoh made another two Keruvim (See Melachim 1, 6:23)?
Riva (citing R. Tam of Orleans): The Prohibition applies to making additional Keruvim on the Kapores, 1 whereas Shlomo made the additional Keruvim on the Aron. 2
Oznayim la'Torah: Refer to 5:8:152:1. The two additional Keruvim that Shlomoh made stood on the ground and were not part of the Kapores.
Why can't we similarly answer that the Isur is "Elohei Kesef v'Elohei Zahav", whereas those of Shlomoh ha'Melech were made primarily of wood, only they were overlaid with gold? Bear in mind that the Chachamim permit a wooden Menorah of seven branches (Avodah Zarah 43a)! Perhaps since it looks like solid gold, it is forbidden. (PF)
How did they rest on the Aron? The Kapores covers the Aron! We must say that it rested on the gold outer covering of the Aron. Sukah 4b says that the outer covering extended above the wooden Aron, opposite the Kapores. How could a a gold wall Mashehu thick support the weight of Keruvim? Refer to 25:11:152:1*.
This is problematic, since a Navi only has the authority to negate a Torah ruling temporarily, but not on a permanent basis?
QUESTIONS ON RASHI
Rashi writes that the Keruvim had the face of a child. What is the significance of this statement?
Vilna Gaon (Chidushei Agados, Bava Kama Perek 8, Michtav me'Eliyahu 5, p. 460, citing a Midrash): It symbolizes Yisrael, who, in their infancy (shortly after they left Egypt, at Keri'as Yam Suf) were afraid of the Egyptians but trusted implicitly in Hashem. 1 Later, when their trust decreased, so did Hashem's Hashgachah. 2
Oznayim la'Torah: The Keruvim were fashioned from the lid and were part of it (and they looked down at the lid of the Aron which housed the Seifer Torah) - to teach us that the Chinuch of a child should be based entirely on Torah. 3
This can be compared to a young chick, whose mother places food in its mouth, but when it gets older, is able feed itself and no longer relies on its mother; and to a child, who depends totally on Hashem, and there is awesome Hashgachah. When he grows lder, he trusts in himself, and the Hashgachah decreases. See also Torah Teemimah, note 23, who elaborates.
Mishnas R. Aharon 4 p.70: A baby who relies on his mother and on no one else, this arouses love from his mother. Likewise, total reliance on Hashem arouses His desire to fulfill all one's requests.
See Oznayim la'Torah who elaborates. The two Keruvim teach us that one should not learn on one's own, but together with a Chavrusa, as the Gemara teaches in B'rachos, 63b (Oznayim la'Torah). And the Torah writes in Pasuk 22 "Vedibarti itcha me'al ha'Kapores", to teach us that, as long as there are children learning Torah, the Shechinah rests in Yisrael and Hashem speaks with the prophets, but 'If the Tinokos shel Bei Rabban have gone into exile, the Shechinah has gone into exile together with them - Oznayim la'Torah citing the Midrash Rabah.