In nearly every passage of Scripture that mentions “chaff driven away,” it’s the wind that does the driving (Job 21:18; Psalm 1:4; 35:5; 83:3; Isaiah 17:13; Daniel 2:35). Yahweh’s Spirit is a wind storm taht drives the wicked away like withered chaff.

Isaiah 41:2 is the exception: There it’s not the wind that drives away but the bow of righteousness: Someone (“Who?”) wakes up righteousness from his slumber at daybreak (“from the east”), and Righteousness comes with a pulverizing sword to turn the nations and kings to dust and with a bow that blows away the chaff. This chaff is “driven” away ( nadaph ; the verb is also used in Leviticus 26:36; Job 13:25; 32:13; Psalm 1:4; 68:2; Proverbs 21:6), not by Yahweh’s breath but by the bow.

That suggests that the bow of Righteousness in Isaiah 41 conjures the image of Yahweh’s storm. As in Psalm 18 and elsewhere, Righteousness rides on the wind, shooting lightning arrows at the wicked.