He believeth not that he shall return out of darkness - Darkness is used in the Bible, as elsewhere, to denote calamity; and the meaning here is, that the wicked man has not confidence (יאמין לא lo' ya'amı̂yn), that he shall return safely from impending danger. He is in constant dread of assassination, or of some fearful evil. He is never secure; his mind is never calm; he lives in constant dread. This is still an accurate description of a man with a guilty conscience; for such a man lives in constant fear, and never feels any security that he is safe.
And he is waited for of the sword - That is, he is destined for the sword. Gesenius.

That he shall return out of darkness - If he take but a few steps in the dark, he expects the dagger of the assassin. This appears to be the only meaning of the place. Some think the passage should be understood to signify that he has no hope of a resurrection; he can never escape from the tomb. This I doubt: in the days of the writer of this book, the doctrine of a future judgment was understood in every part of the East where the knowledge of the true God was diffused.

He believeth not that he shall return out of (n) darkness, and he is waited for of the sword.
(n) Out of that misery to which he once fell.

He believeth not that he shall return out of darkness,.... When he lies down at night he despairs of ever seeing the light of the morning, through fear of an enemy, a robber, a murderer, or of one disaster or another, Deuteronomy 28:66; or when he is in any affliction and calamity, which is often signified by darkness, he cannot persuade himself that he shall ever be delivered out of it, and restored to his former condition again: and here Eliphaz seems to glance at Job, who had no hope of his being brought into such a state of prosperity he had been in; whereas good men, when in darkness, believe they shall be brought again to the light, as the church in Micah 7:8; or the infidel, who knows he must be laid in the dark and silent grave; the Heathen man, such as were many of the neighbours of Eliphaz, the Idumeans, among whom he dwelt, who were without the hope of a glorious resurrection; and which is an article of pure revelation, and which the idolatrous Heathen were strangers to, and so believed it not, or any deliverance from the grave; or this may respect the blackness of darkness, the outer darkness, the darkness of hell, which when once a wicked man is cast into, and enveloped with, he despairs, as he well may, of ever being delivered out of it:
and he is waited for of the sword; or by them that kill with the sword, as the Targum, who lie in wait for him, to rob him, and kill him; or in his own apprehension he seems to have nothing but drawn swords about him, or a sword hanging over his head, or the judgments of God ready to fall upon him for his sins; for he, having killed others with the sword, must expect to be killed with it himself.

darkness--namely, danger or calamity. Glancing at Job, who despaired of restoration: in contrast to good men when in darkness (Micah 7:8-9).
waited for of--that is, He is destined for the sword [GESENIUS]. Rather (in the night of danger), "he looks anxiously towards the sword," as if every sword was drawn against him [UMBREIT].

Believeth not - When he falls into trouble, he despairs of deliverance, by reason of his guilty conscience. Waited for - Besides the calamity which is upon him, he is in constant expectation of greater; the sword is used for any grievous affliction.