7:11,12 And all the angels... and the elders and the four beasts. In Re 5:11-14 the elders, four living creatures, the angels about the throne, and every creature join in the praises. Here again all are named, and the angels worship and join in praising God for the blessed scene they have just beheld.
7:12 Amen - With this word all the angels confirm the words of the great multitude; but they likewise carry the praise much higher. The blessing, and the glory, and the wisdom, and the thanksgiving, and the honour, and the power, and the strength, be unto our God for ever and ever - Before the Lamb began to open the seven seals, a sevenfold hymn of praise was brought him by many angels, Rev 5:12. Now he is upon opening the last seal, and the seven angels are going to receive seven trumpets, in order to make the kingdoms of the world subject to God. All the angels give sevenfold praise to God.
7:9-12 The first fruits of Christ having led the way, the Gentiles converted later follow, and ascribe their salvation to God and the Redeemer, with triumph. In acts of religious worship we come nigh to God, and must come by Christ; the throne of God could not be approached by sinners, were it not for a Mediator. They were clothed with the robes of justification, holiness, and victory; and they had palms in their hands, as conquerors used to appear in their triumphs. Such a glorious appearance will the faithful servants of God make at last, when they have fought the good fight of faith, and finished their course. With a loud voice they gave to God and the Lamb the praise of the great salvation. Those who enjoy eternal happiness must and will bless both the Father and the Son; they will do it publicly, and with fervour. We see what is the work of heaven, and we ought to begin it now, to have our hearts much in it, and to long for that world where our praises, as well as our happiness, will be made perfect.