Why will the Lord stir up the spirit of a destroyer against Babylon?  

The oracle against Babylon continues in Jeremiah 51:1–64 and it begins in Jeremiah 51:1–5 with the Lord yet again announcing that he will stir up the spirit of a destroyer against Babylon. This destroyer is still not named, but it is very clear that it is the Lord sending this invader against Babylon. The name Leb-kamai is what is known as a Hebrew Atbash of the name Babylon. An Atbash is where the letters of the alphabet are swapped, first for the last, second for the second last etc. The result here is that Babylon becomes Leb-kamai which can be understood to mean the heart of those who rise up against me. Babylon is therefore described as the epitome of rebellion against the Lord. It is for this reason that Babylon comes to represent a world in opposition to the Lord in the book of Revelation.¹

The invading force will come to Babylon like a winnower, and like the wheat is removed from the crop, so everything of value will be removed from Babylon and they shall empty the land. This is a day of trouble for Babylon, the day they face the Lord’s judgment.

Babylon’s army will not be able to respond in any meaningful way as they are totally overwhelmed by the invading force. Her soldiers will not even bend their bows or stand up in their armour before being devoted to destruction. The language of being devoted to destruction (see Jeremiah 50:21, Jeremiah 50:26) emphasizes that this is the Lord’s battle.

The restoration of the Lord’s people can never be separated from his judgment of Babylon. So here again we see that, as the Lord is bringing retribution to Babylon, he is also setting his people free. For Israel and Judah have not been forsaken by their God, the Lord of hosts, but the land of the Chaldeans is full of guilt against the Holy One of Israel. The Lord’s people may have experienced his judgment at the hands of the Babylonians, but the cruel, violent, arrogant and idolatrous behaviour of Babylon does not destroy the Lord’s promises and commitment to his covenant people. The sovereign Lord of Hosts, the Holy one of Israel, will work out his perfect covenant purposes despite the wicked behaviour of both his covenant people and rebellious Babylon.