William Burkitt on Revelation 19:2

Observe here, 1. The cause assigned and set down for this their doxology and solemn thanksgivings, namely, the truth and faithfulness, as also the justice and righteousness, of God in the execution of his judgments upon Babylon; his truth appeared in performing the threatening which Babylon despised, and his righteousness in suiting his judgments inflicted upon her, to the sins of idolatry and bloodshed committed by her.

Observe, 2. The title here given to Babylon, she is called the whore, because of her idolatry, which is often in scripture styled spiritual whoredom; and the great whore, because of her universal corrupting the whole earth: she made others to sin, and cruelly murdered those who would not sin.

Hence learn, That idolatry and persecution constantly go together. Babylon's idolatrous practices were accompanied with bloody cruelties.

Observe, 3. An intimation given of the irreparable ruin and irrecoverable destruction of Babylon,--her smoke rose up for ever and ever, that is, God followed her with a succession of plagues and judgments until she was ruined past recovery.

Observe, 4 That the word Alleluia,as it begins the song, so does it also close the same; to show thereby the raisedness of the church's affections, and their unweariedness in praising God for this deliverance of Babylon's destruction.