Jeremiah 51:6 - Matthew Poole's English Annotations on the Holy Bible

It is a matter of no great moment whether we understand these words as spoken to the Jews in the captivity of Babylon, as Jeremiah 1:8, or to those whom the Chaldeans had hired to help them, or to such strangers as for their secular advantages lived in Babylon. By soul here seemeth to be meant life, and by iniquity the punishment of the Babylonians iniquity (as the Hebrew word oft signifies); though in the New Testament these words be used as a monition to people to separate from the idolatries of mystical Babylon, yet they seem here to be only a warning to others to remove out of the reach of Babylon's fall. For this is the time of the Lord's vengeance; he will render unto her a recompence; for the time is come when God hath determined to take vengeance on Babylon, and to recompense to her all her sin, and that cruelty which she showed to the Jews in particular.