They are vanity, the work of errors: in the time of their {l} judgment they shall perish.

(l) When God will execute his vengeance.

Matthew Henry's Concise Commentary

51:1-58 The particulars of this prophecy are dispersed and interwoven, and the same things left and returned to again. Babylon is abundant in treasures, yet neither her waters nor her wealth shall secure her. Destruction comes when they did not think of it. Wherever we are, in the greatest depths, at the greatest distances, we are to remember the Lord our God; and in the times of the greatest fears and hopes, it is most needful to remember the Lord. The feeling excited by Babylon's fall is the same with the New Testament Babylon, Re 18:9,19. The ruin of all who support idolatry, infidelity, and superstition, is needful for the revival of true godliness; and the threatening prophecies of Scripture yield comfort in this view. The great seat of antichristian tyranny, idolatry, and superstition, the persecutor of true Christians, is as certainly doomed to destruction as ancient Babylon. Then will vast multitudes mourn for sin, and seek the Lord. Then will the lost sheep of the house of Israel be brought back to the fold of the good Shepherd, and stray no more. And the exact fulfilment of these ancient prophecies encourages us to faith in all the promises and prophecies of the sacred Scriptures.