Why does it say "Hi ha'Chayah Asher Ra'isi"?
Rashi: I saw in this Merkavah everything that I saw in the first. Therefore, I say that [the angel with four faces] is what I saw in the first (the Chayah).
Malbim (19): The Shechinah is leaving the Mikdash to go with Yisrael to Galus. Therefore, Hashgachah will be clothed to do hidden miracles according to the Ma'arachah; the Keruv will be transformed to a Chayah.
Why does it mention "Asher Ra'isi Tachas Elokei Yisrael"?
Malbim: Also then it was under Elokei Yisrael. So He is called when He supervises over Yisrael with Hashgachah Pratis, just when they are Chayos, the miracles are hidden and the Keruv is hidden.
Why does it say "va'Eda Ki Cheruvim Hemah"?
Rashi: I knew that the face of the ox turned into a Keruv. Now there were two human faces - of a child and of an adult.
Malbim: Now that I saw them a second time in the form of Chayos, I knew that they are Keruvim. Also when they are perceived in the form of Chayos, they are influenced from above, and they are also Keruvim.
