See the strength of his loins and the power in the muscles of his belly.
God, for the further proving of his own power and disproving of Job's pretensions, concludes his discourse with the description of two vast and mighty animals, far exceeding man in bulk and strength, one he calls behemoth, the other leviathan. In these verses we have the former described.
Commenting on Job 40:15-24
He moveth his tail like a cedar,.... To which it is compared, not for the length and largeness of it; for the tail both of the elephant and of the river horse is short; though Vartomannus (c) says, the tail of the elephant is like a buffalo's, and is four hands long, and thin of hair: but because of the smoothness, roundness, thickness, and firmness...
navel--rather, "muscles" of his belly; the weakest point of the elephant, therefore it is not meant.