Jeremiah 51:45

My people, go ye out of the midst of her
This is a call of the Jews to go out of Babylon, not before the taking of the city by Cyrus; but when he should issue out a proclamation, giving them liberty to return to their own land; which many of them, being well settled in Babylon, would not be ready to accept of, but choose to continue there; wherefore they are urged to depart from thence, because of the danger they would be exposed unto; for though the city was not destroyed by Cyrus upon his taking it, yet it was by Darius Hystaspes some time after. The same call is given to the people of God to come out of mystical Babylon, ( Revelation 18:4 ) ; and deliver ye every man his soul from the fierce anger of the Lord;
shown in the destruction of Babylon; (See Gill on Jeremiah 51:6).