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.