Isaiah 48:20

Go ye forth of Babylon,.... Which the Jews had leave to do by the proclamation of Cyrus; and so the people of God will be called to come forth out of mystical Babylon before its destruction, to which these words are applied, Revelation 18:4 perhaps this, in the figurative sense, may be a call to the Christians in Jerusalem, now become another Babylon for wickedness, to come out of it a little before its ruin; and may be applied to the call of persons, by the Gospel, from a state of confusion, sin, and darkness, in which they are:

flee ye from the Chaldeans with the voice of singing; not by stealth, or through fear, but openly and publicly, and with all the tokens and demonstrations of joy and gladness. So the Christians separated, from the unbelieving Jews; as will the followers of the Lamb from the antichristian states, Revelation 19:1 and so all that are called by grace should flee from the company of wicked men:

declare ye, tell this, utter it even to the end of the earth; this shows that something more than deliverance from the Babylonish captivity is here intended; for what had all the ends of the earth to do with that? even redemption and salvation by Christ, typified by it; which the apostles and ministers of the word are here exhorted to declare, publish, and proclaim, to the ends of the earth; Christ having a people there to be called and saved by him; and accordingly such a declaration has been made, Romans 10:18:

say ye, the Lord hath deemed his servant Jacob; as the people of the Jews from the Babylonish captivity, so the people of God, his spiritual Jacob and Israel, his sons and servants, from sin, Satan, and the world, the law, its curses, and condemnation, by the precious blood of Christ, which is the sum and substance of the Gospel declaration.