Jamieson, Fausset and Brown on Ezekiel 1:5

5. Ezekiel was himself of a "gigantic nature, and thereby suited to counteract the Babylonish spirit of the times, which loved to manifest itself in gigantic, grotesque forms" [Hengstenberg].

living creatures--So the Greek ought to have been translated in the parallel passage, Re 4:6, not as English Version, "beasts"; for one of the "four" is a man, and man cannot be termed "beast." Eze 10:20 shows that it is the cherubim that are meant.

likeness of a man--Man, the noblest of the four, is the ideal model after which they are fashioned (Eze 1:10; Eze 10:14). The point of comparison between him and them is the erect posture of their bodies, though doubtless including also the general mien. Also the hands (Eze 10:21).