But cherubim is a much more interesting word than kibbutzim. In medieval and Renaissance English, it was taken to be a singular form. This is why, when the Hebrew book of Genesis tells us that after Adam and Eve were driven from the Garden of Eden, God put k’ruvim at its entrance to keep humanity from returning there, the 1611 King James Version gives us, “And he [God] placed at the east of the garden of Eden cherubims.”Sounds plausible overall. That said, I'm not a Latin paleographer, but I'm pretty sure that capitalization of names came well after the time of Jerome.
Ultimately, this goes back to the standard Latin Bible, which translates these words as et collocavit antes paradisum voluptatis Cherubim. Why Jerome, this Bible’s fourth-century translator, did not render the plural of the Hebrew k’ruv as cherubi or cherubes, in the Latin manner, is explained by his decision to capitalize it. He did not, that is, construe k’ruvim as a plural, but rather as the proper name of some kind of supernatural creature placed by God to guard the Gates of Eden — and as a result, cherubim or cherubin entered a large number of European languages with such a meaning.
[...]
What led Jerome, an accomplished Hebraist in his own right, to make such a mistake? He would seem to have been influenced by a vision of many cherubim in Chapter 10 of the book of Ezekiel, in which each cherub seen by the prophet is depicted as a composite creature, so that “every one had four faces: the first face was the face of a cherub, and the second face was the face of a man, and the third the face of a lion, and the fourth the face of an eagle.” Since Jerome translates the first part of this as Quattuor autem facies habebat unum: facies una, facies cherub, he apparently understood the singular Hebrew noun k’ruv to be the “cherub-face” of a four-faced creature called k’ruvim in both the singular and the plural, just as our English word “fish” can mean either one fish or many.
Philologos also has a theory about how cherubim came to be pictures as cute little babies. That representation is quite different from the intimidating aspect they present in the Bible and in Jewish and Christian mysticial literature. I believe C. S. Lewis once commented that "cherub" is cognate with "gryphon," and that should tell us something. I don't know whether his etymology is right, but the comparison does give a good feel for what the cherubim are like.
I'm extremely busy today, so further blogging may end up on the back burner.