17:12-14 The rage and force of the Assyrians resembled the mighty waters of the sea; but when the God of Israel should rebuke them, they would flee like chaff, or like a rolling thing, before the whirlwind. In the evening Jerusalem would be in trouble, because of the powerful invader, but before morning his army would be nearly cut off. Happy are those who remember God as their salvation, and rely on his power and grace. The trouble of the believers, and the prosperity of their enemies, will be equally short; while the joy of the former, and the destruction of those that hate and spoil them, shall last for ever.
13. shall … shall—rather, "God rebuketh (Ps 9:5) them, and they flee—are chased"; the event is set before the eyes as actually present, not future.
chaff of … mountains—Threshing floors in the East are in the open air on elevated places, so as to catch the wind which separates the chaff from the wheat (Ps 88:13; Ho 13:3).
rolling thing—anything that rolls: stubble.