Origins and etymology
A pair of shedu
protecting a doorway (the bodies of the creatures extend into the distance)
Mythological hybrids are common in the art of the Ancient Near East. One example is the Babylonian lamassu or shedu, a protective spirit with a sphinx-like form, possessing the wings of an eagle, the body of a lion, and the head of a king.
This was adopted largely in Phoenicia. The wings, because of their artistic beauty, soon became the most prominent part, and animals of various kinds were adorned with wings; consequently, wings were bestowed also upon man, thus forming the stereotypical image of an angel.
Albright (1938) argued that "the winged lion with human head" found in Phoenicia and Canaan from the Late Bronze Age is "much more common than any other winged creature, so much so that its identification with the cherub is certain".
A possibly related source is the human-bodied Hittite griffin, which, unlike other griffins, appear almost always not as a fierce bird of prey, but seated in calm dignity, like an irresistible guardian of holy things; some have proposed that the word griffin (γρύψ) may be cognate with cherubim. The traditional Hebrew conception of cherubim as guardians of the Garden of Eden is backed by the Semitic belief of beings of superhuman power and devoid of human feelings, whose duty it was to represent the gods, and as guardians of their sanctuaries to repel intruders; these conceptions in turn are similar to an account found on Tablet 9 of the inscriptions found at Nimrud. It has been suggested that the image of cherubim as storm winds explains why they are described as being the chariot of Yahweh in Ezekiel's visions, the Books of Samuel, the parallel passages in the later Books of Chronicles, and passages in the early Psalms: for example "and he rode upon a cherub and did fly: and he was seen upon the wings of the wind." In particular, in a scene reminiscent of Ezekiel's dream, the Megiddo Ivories depict an unknown king being carried on his throne by hybrid winged-creatures.
Delitzch (Assyrisches Handwörterbuch) connects the name it with Assyrian kirubu (a name of the shedu) and karabu ("great, mighty"). Karppe (1897) glosses Babylonian karâbu as "propitious" rather than "mighty".
Dhorme (1926) connected the Hebrew name to Assyrian kāribu (diminutive kurību), a term used to refer to intercessory beings (and statues of such beings) that plead with the gods on behalf of humanity. The folk etymological connection to a Hebrew word for "youthful" is due to Abbahu (3rd century).