This emphasizes how weak and insignificant the invading army is before God. Alternate translation: "Yahweh will easily remove the horde of your invaders and the multitude of the ruthless ones"(See: [[rc://en/ta/man/translate/figs-simile]])
The translator can supply the verb "will become." Alternate translation: "the ruthless ones will become as chaff" or "the soldiers who show you no mercy will become as chaff" (See: [[rc://en/ta/man/translate/figs-ellipsis]] and [[rc://en/ta/man/translate/figs-explicit]])