New Defender's Study Bible Notes
16:7 heard another out of the altar say. This is probably the unified voice of all “the souls of them that were slain,” including all the tribulation martyrs still resting “under the altar” (Revelation 6:9).
16:7 true and righteous are thy judgments. The saints will agree with the angel that “they are worthy” (Revelation 16:6), since all the ungodly of the world had rejoiced vicariously in the slaying of the two witnesses (Revelation 11:10), and, no doubt, in the execution of all those who had not compromised, as they had.