Matthew Henry Commentary Job 40:15-24

"Behold now, behemoth, which I made as well as thee; He eateth grass as an ox. Lo now, his strength is in his loins, And his force is in the muscles of his belly. He moveth his tail like a cedar: The sinews of his thighs are knit together. His bones are [as] tubes of brass; His limbs are like bars of iron. He is the chief of the ways of God: He [only] that made him giveth him his sword. Surely the mountains bring him forth food, Where all the beasts of the field do play. He lieth under the lotus-trees, In the covert of the reed, and the fen. The lotus-trees cover him with their shade; The willows of the brook compass him about. Behold, if a river overflow, he trembleth not; He is confident, though a Jordan swell even to his mouth. Shall any take him when he is on the watch, Or pierce through his nose with a snare?" — Job 40:15-24 (ASV)

God, to further prove His own power, describes two vast animals, far exceeding humans in bulk and strength. Behemoth signifies beasts. Most understand this to be an animal well known in Egypt, called the river-horse, or hippopotamus.

This vast animal is presented as an argument to humble ourselves before the great God, for He created this vast animal, which is so fearfully and wonderfully made. Whatever strength this or any other creature has, it is derived from God. He who made the soul of man knows all the ways to it, and can make the sword of justice, His wrath, to approach and touch it.

Every godly believer has spiritual weapons, the whole armor of God, to resist, and indeed, to overcome the tempter, so that their never-dying soul may be safe, whatever becomes of their frail flesh and mortal body.