And the land shall tremble and sorrow: for every purpose of the LORD shall be performed against Babylon, to make the land of Babylon a desolation without an inhabitant.
The Prophet no doubt endeavored to remove all doubts from the minds of the godly, which would have otherwise weakened confidence in his doctrine. It might have occurred to the minds of all, that the whole world would sooner come to nothing than that Babylon should fall. Though it were so, says the Prophet, that the whole earth trembled, yet Babylon will be destroyed.
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
One post shall run to meet another, and one messenger to meet another,.... That is, one post should be after another, and one messenger after another, post upon post, and messenger upon messenger, as fast as they could run; when one had been with his message, and delivered it, and returned, he meets another; or they met one another, coming from different places: to show...