The fall of Babylon being fixed, finished, and declared to be irrecoverable in the foregoing chapter, this begins with a holy triumph over her, in pursuance of the order given forth: Rejoice over her, thou heaven, and you holy apostles and prophets, Rev 18:20. They now gladly answer the call; and here you have, 1. The form of their thanksgiving, in that heavenly and most comprehensive word, Alleluia, praise you the Lord: with this they begin, with this they go on, and with this they end (Rev 19:4); their prayers are now turned into praises, their hosannas end in halleluias. 2. The matter of their thanksgiving: they praise him for the truth of his word, and the righteousness of his providential conduct, especially in this great event - the ruin of Babylon, which had been a mother, nurse, and nest of idolatry, lewdness, and cruelty (Rev 19:2), for which signal example of divine justice they ascribe salvation, and glory, and honour, and power, unto our God. 3. The effect of these their praises: when the angels and saints cried Alleluia, her fire burned more fiercely and her smoke ascended for ever and ever, Rev 19:3. The surest way to have our deliverances continued and completed is to give God the glory of what he has done for us. Praising God for what we have is praying in the most effectual manner for what is yet further to be done for us; the praises of the saints blow up the fire of God's wrath against the common enemy. 4. The blessed harmony between the angels and the saints in this triumphant song, Rev 19:4. The churches and their ministers take the melodious sound from the angels, and repeat it; falling down, and worshipping God, they cry, Amen, Alleluia.

For true and righteous - His judgments displayed in supporting his followers, and punishing his enemies, are true - according to his predictions; and righteous, being all according to infinite justice and equity.

For true and righteous are his judgments,.... As in See Gill on Rev 15:3; see Gill on Rev 16:7, this is to be understood of God's judgments in general, and is a reason of the attribution of praise and glory to him; which may be said to be true, because, being threatened, are now fulfilled; and to be "righteous", because according to the demerit of sin; and particularly God's judgments on antichrist are intended:

for he hath judged the great whore; Jezebel, Babylon, the Romish antichrist, before spoken of, Rev 17:1 not only by passing a sentence of condemnation on her, but by executing it, putting it into the hearts of the kings to hate and burn her, and utterly destroy her; and which is judging right, since it follows:

which did corrupt the earth with her fornication; drew the kings and inhabitants of the Roman empire into wicked and idolatrous practices, and so corrupted and destroyed them in soul, body, and estate; See Gill on Rev 11:18 for this vision is contemporary with the seventh trumpet:

and hath avenged the blood of his servants at her hand; shed by her, Rev 18:20 and this being done in righteous judgment, is matter of joy and praise to the saints.

which did corrupt the earth--Greek, "used to corrupt" continually. "Instead of opposing and lessening, she promoted the sinful life and decay of the world by her own earthliness, allowing the salt to lose its savor" [AUBERLEN].

avenged--Greek, "exacted in retribution." A particular application of the principle (Gen 9:5).

blood of his servants--literally shed by the Old Testament adulterous Church, and by the New Testament apostate Church; also virtually, though not literally, by all who, though called Christians, hate their brother, or love not the brethren of Christ, but shrink from the reproach of the cross, and show unkindness towards those who bear it.