The snare is laid - All this language is taken from the modes of taking wild beasts; but it is not possible to designate with absolute certainty the methods in which it was done. The word used here (חבל chebel) means a cord, or rope; and then a snare, gin, or toil, such as is used by hunters. It was used in some way as a noose to secure an animal. This was concealed (Hebrew) "in the earth" - so covered up that an animal would not perceive it, and so constructed that it might be made to spring upon it suddenly.
And a trap - We have no reason to suppose that at that time they employed steel to construct traps as we do now, or that the word here has exactly the sense which we give to it. The Hebrew word (מלכדת malkôdeth) is from לכד lâkad - "to take," "to catch," and means a noose, snare, spring - by which an animal was seized. It is a general term; though undoubtedly used to denote a particular instrument, then well known. The general idea in all this is, that the wicked man would be suddenly seized by calamities, as a wild animal or a bird is taken in a snare. Independently of the interest of the entire passage Job 18:8-10 as a part of the argument of Bildad, it is interesting from the view which it gives of the mode of securing wild animals in the early periods of the world. They had no guns as we have; but they early learned the art of setting gins and snares by which they were taken. In illustrating this passage, it will not be inappropriate to refer to some of the modes of hunting practiced by the ancient Egyptians. The same methods were practiced then in catching birds and taking wild beasts as now, and there is little novelty in modern practices. The ancients had not only traps, nets, and springs, but also bird-lime smeared upon twigs, and made use of stalking-horses, setting dogs, etc. The various methods in which this was done, may be seen described at length in Wilkinson's Manners and Customs of the Ancient Egyptians, vol. iii. pp. 1-81. The noose was employed to catch the wild ox, the antelope, and other animals.
This seems to be a self-acting net, so constructed that the birds, when coming in contact with it, close it upon themselves.
This trap appears as if in a vertical position, although, doubtless, it is intended to represent a trap lying upon the ground.
There are other traps very similar to this, except that they are oval; and probably have a net like the former. They are composed of two arcs, which, being kept open by machinery in the middle, furnish the oval frame of the net; but when the bird flies in, and knocks out the pin in the center, the arcs collapse enclosing the bird in the net. One instance occurs, in a painting at Thebes, of a trap, in which a hyaena is caught, and carried on the shoulders of two men. It was a common method of hunting to enclose a large tract of land by a circle of nets, or to station men at convenient distances, and gradually to contract the circle by coming near to each other, and thus to drive all the wild animals into a narrow enclosure, where they could be easily slain. Some idea of the extent of those enclosures may be formed from the by no means incredible circumstance related by Plutarch, that when the Macedonian conquerors were in Persia, Philotos, the son of Armenio, had hunting-nets that would enclose the space of an hundred furlongs. The Oriental sovereigns have sometimes employed whole armies in this species of hunting. Picture Bible.

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", Proverbs 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 in the earth, or in some private place, where the creature it is designed for may be thought to come, or into which it is decoyed; or "the cord" (s), that which is fastened to the snare or net, and which the fowler holds in his hand, and pulls with; as he finds occasion and opportunity offers; but this is hid as much as possible, that it may not be seen:
and a trap for him in the way; in which he is used to walk, by the roadside, or in it; Mr. Broughton renders it, "a pitfall on the wayside", such as is dug for beasts to fall into and be taken. The whole of this is designed to show how suddenly and secretly wicked men are taken in nets, and snares, and gins, either of their own or others laying, and, while they are crying "Peace, peace, sudden destruction comes upon them"; see Ecclesiastes 9:12.
(r) "absconditus", V. L. Pagninus, Montanus, Junius & Tremellius, &c. (s) "funis ejus", Montanus, Tigurine version, Mercerus, Drusius, Cocceius, Schmidt.