Possible meaning are 1) "Yahweh will destroy the great forests and farmlands in the nation of Assyria" or 2) "Yahweh will destroy the army of Assyria as a fire burns up great forests and farmlands." (See: [[rc://en/ta/man/jit/figs-metaphor]])
Possible meanings are 1) this emphasizes that God will completely destroy the forests and farmlands. Alternate translation: "completely" or 2) this means God will completely destroy the people of Assyria. The phrase "soul and body" refers to the spiritual part and the physical part of a person. (See: [[rc://en/ta/man/jit/figs-merism]])
This compares either the forests and farmlands of Assyria or the army of Assyria to a sick man as he lies in bed dying. This emphasizes how something so great can become weak and dying. Alternate translation: "they will be like a sick man who grows weak and dies" (See: [[rc://en/ta/man/jit/figs-simile]])