A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
job 18:2REPLY OF BILDAD. (Job 18:1-21)
ye--the other two friends of Job, whom Bildad charges with having spoken mere "words," that is, empty speeches; opposed to "mark," that is, come to reason, consider the question intelligently; and then let us speak.
job 18:3beasts--alluding to what Job said (Job 12:7; so Isa 1:3).
vile--rather from a Hebrew root, "to stop up." "Stubborn," answering to the stupidity implied in the parallel first clause [UMBREIT]. Why should we give occasion by your empty speeches for our being mutually reputed, in the sight of Job and one another, as unintelligent? (Job 17:4, Job 17:10).
job 18:4Rather, turning to Job, "thou that tearest thyself in anger" (Job 5:2).
be forsaken?--become desolate. He alludes here to Job's words as to the "rock," crumbling away (Job 14:18-19); but in a different application. He says bitterly "for thee." Wert thou not punished as thou art, and as thou art unwilling to bear, the eternal order of the universe would be disturbed and the earth become desolate through unavenged wickedness [UMBREIT]. Bildad takes it for granted Job is a great sinner (Job 8:3-6; Isa 24:5-6). "Shall that which stands fast as a rock be removed for your special accommodation?"
job 18:5That (Job 18:4) cannot be. The decree of God is unalterable, the light (prosperity) of the wicked shall at length be put out.
his fire--alluding to Arabian hospitality, which prided itself on welcoming the stranger to the fire in the tent, and even lit fires to direct him to it. The ungodly shall be deprived of the means to show hospitality. His dwelling shall be dark and desolate!
job 18:6candle--the lamp which in the East is usually fastened to the ceiling. Oil abounds in those regions, and the lamp was kept burning all night, as now in Egypt, where the poorest would rather dispense with food than the night lamp (Psa 18:28). To put out the lamp was an image of utter desolation.
job 18:7steps of his strength--Hebrew, for "His strong steps." A firm step marks health. To be straitened in steps is to be no longer able to move about at will (Pro 4:12).
his own counsel--Plans shall be the means of his fall (Job 5:13).
job 18:8he walketh upon--rather, "he lets himself go into the net" [UMBREIT]. If the English Version be retained, then understand "snare" to be the pitfall, covered over with branches and earth, which when walked upon give way (Psa 9:15; Job 35:8).
job 18:9robber--rather answering to "gin" in the parallel clause, "the noose shall hold him fast" [UMBREIT].
job 18:11Terrors--often mentioned in this book (Job 18:14; Job 24:17; &c.). The terrors excited through an evil conscience are here personified. "Magor-missabib" (Jer 20:3).
drive . . . to his feet--rather, "shall pursue" (literally, "scatter," Hab 3:14) him close "at his heels" (literally, "immediately after his feet," Hab 3:5; Sa1 25:42; Hebrew). The image is that of a pursuing conqueror who scatters the enemy [UMBREIT].
job 18:12The Hebrew is brief and bold, "his strength is hungry."
destruction--that is, a great calamity (Pro 1:27).
ready at his side--close at hand to destroy him (Pro 19:29).
job 18:13UMBREIT has "he" for "it," that is, "in the rage of hunger he shall devour his own body"; or, "his own children" (Lam 4:10). Rather, "destruction" from Job 18:12 is nominative to "devour."
strength--rather, "members" (literally, the "branches" of a tree).
the first-born of death--a personification full of poetical horror. The first-born son held the chief place (Gen 49:3); so here the chiefest (most deadly) disease that death has ever engendered (Isa 14:30; "first-born of the poor"--the poorest). The Arabs call fever, "daughter of death."
job 18:14confidence--all that the father trusted in for domestic happiness, children, fortune, &c., referring to Job's losses.
rooted out--suddenly torn away, it shall bring--that is, he shall be brought; or, as UMBREIT better has, "Thou (God) shalt bring him slowly." The Hebrew expresses, "to stride slowly and solemnly." The godless has a fearful death for long before his eyes, and is at last taken by it. Alluding to Job's case. The King of terrors, not like the heathen Pluto, the tabled ruler of the dead, but Death, with all its terrors to the ungodly, personified.
job 18:15It--"Terror" shall haunt, &c., and not as UMBREIT, "another," which the last clause of the verse disproves.
none of his--It is his no longer.
brimstone--probably comparing the calamity of Job by the "fire of God" (Job 1:16) to the destruction of guilty Sodom by fire and brimstone (Gen 19:24).
branch--his children (Job 8:12; Job 15:30; Mal 4:1).
job 18:17street--Men shall not speak of him in meeting in the highways; rather, "in the field" or "meadow"; the shepherds shall no more mention his name--a picture from nomadic life [UMBREIT].
job 18:18light . . . darkness--existence--nonexistence.
job 18:19nephew--(so Isa 14:22). But it is translated "grandson" (Gen 21:23); translate "kinsman."
job 18:20after . . . before--rather, "those in the West--those in the East"; that is, all people; literally, "those behind--those before"; for Orientals in geography turn with their faces to the east (not to the north as we), and back to the west; so that before--east; behind--north (so Zac 14:8).
day--of ruin (Oba 1:12).
affrighted--seized with terror (Job 21:6; Isa 13:8).
job 18:21(Job 8:22, Margin).