Saying to the sixth angel who had the trumpet,
Loose the four angels who are bound in the great river Euphrates.
All Commentaries on Revelation 9:14 Go To Revelation 9
Victorinus of Pettau
AD 303
By the corners of the earth, or the four winds across the river Euphrates, are meant four nations, because to every nation is sent an angel; as said the law, He determined them by the number of the angels of God, until the number of the saints should be filled up. They do not overpass their bounds, because at the last they shall come with Antichrist.
