The word "sword" refers to Judah's enemies. Also, the word "devour" compares Judah's enemies coming to kill them to a wild animal that attacks and eats other animals. Alternate translation: "your enemies will kill you" (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-metaphor]])
The word "mouth" emphasizes that Yahweh has spoken and what he says will certainly happen. Alternate translation: "Yahweh has spoken" or "Yahweh has said that this will happen" (See: [[rc://en/ta/man/jit/figs-synecdoche]])