Revelation 9:13 in the World English Bible
The sixth angel sounded. I heard a voice from the horns of the golden altar which is before God,
Context
12 One woe is past; and, behold, there come two woes more hereafter.
13 And the sixth angel sounded, and I heard a voice from the four horns of the golden altar which is before God,
14 Saying to the sixth angel which had the trumpet, Loose the four angels which are bound in the great river Euphrates.