Albert Barnes Commentary Job 24:17

"For the morning is to all of them as thick darkness; For they know the terrors of the thick darkness." — Job 24:17 (ASV)

For the morning is to them even as the shadow of death - They dread the light as one usually does the deepest darkness. The morning or light would reveal their deeds of wickedness, and they therefore avoid it.

As the shadow of death - As the deepest darkness; see the notes at (Job 3:5).

If one know them - If they are recognized. Or, more probably, this means “they,” that is, each one of them, “are familiar with the terrors of the shadow of death,” or with the deepest darkness. By this rendering the common meaning of the word (יכיר yakı̂yr) will be retained, and the translation will accord with the general sense of the passage.

The meaning is that they are familiar with the blackest night. They do not dread it. They dread only the light of day. To others the darkness is terrible; to them it is familiar. The word rendered “shadow of death” in the latter part of this verse is the same as in the former.

It may mean in both places the gloomy night that resembles the shadow of death. Such a night is “terrible” to most people; to them it is familiar, and they feel secure only when its deep shades are around them.