I will send strangers to Babylon to winnow her and empty her land; for they will come against her from every side in her day of disaster.
Here he explains himself more clearly, without the metaphor he had used. He no longer uses the similitude of wind when he declares that he would send fanners At the same time some take זארים, zarim, in the sense of aliens, who would banish her; but this would be harsh. I then doubt not but that the Prophet alludes to the wind before mentioned.
Babylon was once a golden cup in the Lord's hand, filled with His favor, but also His battle-axe to break nations. Those that carry all before them a great while will yet meet their match; even Babylon's day will come, and it too shall fall.
AI summary
Commenting on Jeremiah 51:1-58
And I will send unto Babylon farmers, that shall fan her, and shall empty her land,.... Or, "strangers that shall fan her" (c); meaning the Medes and Persians, who should be like a strong wind upon the mountains, where corn, having been threshed, was fanned, and the chaff carried away by the wind; and such would the Chaldeans be in the hand of the Persians...