en_tn/jer/04/28.md

the land will mourn, and the heavens above will darken

Jeremiah emphasizes Yahweh's judgment by saying that the earth itself expresses great sorrow. (See: rc://en/ta/man/jit/figs-personification)

I will not hold back

"I will not change my mind"

I will not turn from carrying them out

Here "turn" represents deciding not to do what he said he would do. Alternate translation: "I will not change my mind about doing what I said I would do" or "I will not refuse to do what I planned to do" (See: rc://en/ta/man/jit/figs-metaphor)