Albert Barnes Commentary Revelation 19:3

"And a second time they say, Hallelujah. And her smoke goeth up for ever and ever." — Revelation 19:3 (ASV)

And again they said, Alleluia.

The event was so glorious and so important; the final destruction of the great enemy of the church was so significant in its bearing on the welfare of the world as to call forth repeated expressions of praise.

And her smoke rose up for ever and ever.

This is an image of final ruin; the image is probably derived from the description in Genesis of the smoke that ascended from the cities of the plain, Genesis 19:28. On the joy expressed here in her destruction, compare Revelation 18:20.