Psalms 18:42

Then did I beat them small as the dust before the wind - As the fine dust is driven by the wind, so they fled before me. There could be no more striking illustration of a defeated army flying before a conqueror. DeWette says correctly that the idea is, “I beat them small, and scattered them as dust before the wind.”

I did cast them out as the dirt in the streets - In the corresponding place in 2 Samuel 22:43, this is, “I did stamp them as the mire of the street, and did spread them abroad.” The idea in the place before us is, that he poured them out, for so the Hebrew word means, as the dirt or mire in the streets. As that is trodden on, or trampled down, so they, instead of being marshalled for battle, were wholly disorganized, scattered, and left to be trodden down, as the most worthless object is. A similar image occurs in Isaiah 10:6, where God is speaking of Sennacherib: “I will send him against an hypocritical nation ... to tread them down like the mire of the streets.”