3:1-10 For seven days Job's friends sat by him in silence, without offering consolidation: at the same time Satan assaulted his mind to shake his confidence, and to fill him with hard thoughts of God. The permission seems to have extended to this, as well as to torturing the body. Job was an especial type of Christ, whose inward sufferings, both in the garden and on the cross, were the most dreadful; and arose in a great degree from the assaults of Satan in that hour of darkness. These inward trials show the reason of the change that took place in Job's conduct, from entire submission to the will of God, to the impatience which appears here, and in other parts of the book. The believer, who knows that a few drops of this bitter cup are more dreadful than the sharpest outward afflictions, while he is favoured with a sweet sense of the love and presence of God, will not be surprised to find that Job proved a man of like passions with others; but will rejoice that Satan was disappointed, and could not prove him a hypocrite; for though he cursed the day of his birth, he did not curse his God. Job doubtless was afterwards ashamed of these wishes, and we may suppose what must be his judgment of them now he is in everlasting happiness.

5. Let … the shadow of death—("deepest darkness," Isa 9:2).

stain it—This is a later sense of the verb [Gesenius]; better the old and more poetic idea, "Let darkness (the ancient night of chaotic gloom) resume its rights over light (Ge 1:2), and claim that day as its own."

a cloud—collectively, a gathered mass of dark clouds.

the blackness of the day terrify it—literally, "the obscurations"; whatever darkens the day [Gesenius]. The verb in Hebrew expresses sudden terrifying. May it be suddenly affrighted at its own darkness. Umbreit explains it as "magical incantations that darken the day," forming the climax to the previous clauses; Job 3:8 speaks of "cursers of the day" similarly. But the former view is simpler. Others refer it to the poisonous simoom wind.