en_tn/deu/07/10.md

repays those who hate him to their face

This idiom means "repays them quickly and openly so that they know God has punished them." (See: rc://en/ta/man/jit/figs-idiom)

he will not be lenient on whoever hates him

The words "not be lenient" are an understatement to emphasize that Yahweh will severely punish. Alternate translation: "Yahweh will severely punish everyone who hates him" (See: rc://en/ta/man/jit/figs-litotes)