Albert Barnes Commentary Job 8:18

"If he be destroyed from his place, Then it shall deny him, [saying], I have not seen thee." — Job 8:18 (ASV)

If he destroy him from his place—The particle here that is rendered "if" (אם 'ı̂m) is often used to denote emphasis, and means here "certainly"—"he will be certainly destroyed." The word rendered "destroy," from בלע bela‛—means literally to swallow (Job 7:19), to swallow up, to absorb; and so, to consume, lay waste, destroy. The sense is that the wicked or the hypocrite will be completely destroyed from his place, but the image or figure of the tree is still retained. Some suppose that it means that God would destroy him from his place; others, as Rosenmuller and Dr. Good, suppose that the reference is to the soil in which the tree was planted, that it would completely absorb all nutriment, and leave the tree to die. That is, the dry and thirsty soil in which the tree is planted, instead of affording nutriment, acts as a "sucker," and itself absorbs all the juices that would otherwise give support to the tree. This seems to me to be probably the true interpretation.

It is one drawn from nature, and one that preserves the harmony of the passage.

Then it shall deny him—That is, the soil, the earth, or the place where it stood. This represents a wicked man under the image of a tree. The figure is beautiful. The earth will be ashamed of it; ashamed that it sustained the tree; ashamed that it ever ministered any nutriment, and will refuse to own it. So with the hypocrite. He will pass away as if the earth refused to own him, or to retain any recollection of him.

I have not seen thee—I never knew thee. It will utterly deny any acquaintance with it. There is a striking resemblance here to the language that the Savior says He will use respecting the hypocrite in the day of judgment: and then will I profess to them, I never knew you; (Matthew 7:23). The hypocrite has never been known as a pious man. The earth will refuse to own him as such, and so will the heavens.