Adam Clarke on Revelation 19:6

The voice of a great multitude - This is the catholic or universal Church of God gathered from among the Gentiles.

The Lord God Omnipotent reigneth - Εβασιλευσε Κυριος ὁ Θεος ὁ παντοκρατωρ. Many excellent MSS., most of the versions, with Andreas and Arethas, the two most ancient commentators on this book, add ἡμων, our, after ὁ Θεος· and according to this the text reads emphatically thus: Our Lord God, the Almighty, reigneth. What consolation to every genuine Christian that His Lord and God is the Almighty, and that this Almighty never trusts the reins of the government of the universe out of his hands! What therefore has his Church to fear?