Here Job's "heart" represents his inner being. AT: "my plans will never happen, nor will the things that I have desired most" (See: [[rc://en/ta/man/translate/figs-metonymy]])
These two phrases refer to the same people, namely Job's friends, Eliphaz, Bildad, and Zophar. The second phrase emphasizes their unfriendly attitude. (See: [[rc://en/ta/man/translate/figs-doublet]])
This speaks of the people claiming that night is day as if they actually changed night into day. AT: "claim it is daytime when it is night" or "say the opposite of what is true, just as night is the opposite of day" (See: [[rc://en/ta/man/translate/figs-metaphor]])
It is implied that the mockers claim that it is light when it is close to dark. AT: "they claim that light is near to darkness" or "they claim that when it is becoming dark, that it is getting light" (See: [[rc://en/ta/man/translate/figs-explicit]])