Amos 5:20

“[Shall] not the day of the Lord [be] darkness, and not light? etc.] The design of such a question is strongly to affirm, that, in this day of the Lord spoken of, there should be nothing but misery and distress, and no prosperity and happiness, at least to the wicked Israelites, or the unbelieving Jews: even very dark, and no brightness in it? signifying that there should be no deliverance, nor the least glimmering view or hope of it; that the calamity should be so very great, and the destruction so entire, that there should be no mixture of mercy, nor the least appearance of relief.”

“Shall not the Day of the Lord be darkness? - He had described that Day as a day of inevitable destruction, such its man’s own conscience and guilty fears anticipate, and then appeals to their own consciences, “is it not so, as I have said?” People’s consciences are truer than their intellect. However, they may employ the subtlety of their intellect to dull their conscience, they feel, in their heart of hearts, that there is a Judge, that guilt is punished, that they are guilty. The soul is a witness to its own deathlessness, its own accountableness, its own punishableness . Intellect carries the question out of itself into the region of surmising and disputings. Conscience is compelled to…”

“darkness: Job 3:4-6, Job 10:21, Job 10:22; Isa 13:10; Eze 34:12; Nah 1:8; Mat 22:13; Jde 1:13; Rev 16:10 Amos 5:21”