Rev. 12:10 – Then I heard a loud voice in heaven say: The salvation and the power and the kingdom of our God and the authority of His Messiah have now come, because the accuser of our brothers has been thrown out: the one who accuses them before God day and night. (HCSB)
A loud voice in heaven
In verse 10 John records, “Then I heard a loud voice in heaven.” We are not told whose voice utters this celebratory hymn, just as in previous passages in Revelation we are not always given the identity of those speaking. The emphasis here is not on the messenger but on the message. We may, however, rule out an angelic source to the voice in heaven because of the words “the accuser of our brothers” (v. 10b). Satan accuses sinful and fallen people, not angels, before God. Further, scripture does not refer to the angelic host as “brothers.” So, it’s possible the voice in heaven is that of Jesus on behalf of the redeemed – or, more likely, the combined voices of the martyrs before the throne.
It is fitting that we hear a song, for the people of God often raise their voices in praise when they witness the miraculous deeds of our sovereign God. In the Old Testament, for example, there is the song of Moses at the Red Sea (Ex. 15); the song of Deborah after the Lord delivers Israel from Jabin the king of Canaan (Judges 5); and the song of David, when the Lord delivers him out of the hand of all his enemies (2 Sam. 22). In the New Testament, followers of Jesus compose hymns of praise to honor Him for His finished work on the cross, and singing becomes an integral part of worship (for example, see Acts 16:24-26; 1 Cor. 14:25-27; Eph. 5:19; Col. 3:16).
In this passage in Revelation, there is particular cause for joy. “On no occasion could such a song be more appropriate than on the complete routing and discomfiture of Satan and his rebellious hosts” (Barnes’ Notes on the Bible, Rev. 12:10).