A trap seizes his heel; a snare grips him.
The rest of Bildad's discourse is entirely taken up in an elegant description of the miserable condition of a wicked man, in which there is a great deal of certain truth, and which will be of excellent use if duly considered - that a sinful condition is a sad condition, and that iniquity will be men's ruin if they do not repent of it.
Commenting on Job 18:5-10
The snare is laid for him in the ground,.... Or "hidden" (r) there; for, as Solomon says, "in vain the net is spread in sight of any bird", Pro 1:17; and in vain it is to lay a snare publicly in the sight or creature, it will not then come near it, but shun and avoid it; and therefore it is laid underground, or hid...
robber--rather answering to "gin" in the parallel clause, "the noose shall hold him fast" [UMBREIT].