RobH_en_tn/jer/25/38.md

Like a young lion, he has left his den

Yahweh punishing his people in his extreme wrath is spoken of as if Yahweh were a lion who leaves his den in search of prey. (See: rc://en/ta/man/translate/figs-metaphor)

their land will become a horror

The word "horror" may be translated with a verbal phrase. Alternate translation: "their land will become something that horrifies people" (See: rc://en/ta/man/translate/figs-abstractnouns)

the oppressor's anger

This refers to the anger of Israel's enemies.