Jeremiah 51:20-24 - Joseph Benson’s Commentary on the Old and New Testaments

Thou art my battle-axe, &c. Cyrus, or rather the army of the Medes and Persians, seems to be intended here; compare Jeremiah 51:11-12; as elsewhere the instrument of God's vengeance is called a sword, a rod, a scourge. This army, with Cyrus, their general, God here says he will make use of for destroying the whole power of the Babylonish empire, and all orders and degrees of men in it, as he had formerly made that empire the executioner of his judgments upon other countries, Jeremiah 50:23. “Or else,” says Lowth, “the words may be understood of the church, and imply, that God will destroy all those earthly powers and kingdoms which are adversaries to his truth and people, in order to establish and advance his church. This will be fulfilled at the fall of mystical Babylon, when God's kingdom shall break in pieces all the kingdoms of the earth, in the destruction of that remnant of the fourth monarchy, according to Daniel's prophecy, Daniel 2:44.” And I will render unto Babylon all their evil (see Jeremiah 51:11, and Jer 50:28) that they have done in Zion, in your sight This may either refer to the evil done at Jerusalem and in Judea, by the Chaldeans, in the sight of God's people, or to the open and public manner in which judgment would be executed on Babylon.