Matthew Poole and continuators on Revelation 8:6

6 And the seven angels which had the seven trumpets, prepared themselves to sound .

The Angels are God's Ministers by which he bringeth his Counsels to pass in the World: they hearing the Thunders and Voices, knew the time was come when they were to begin the Execution of God's Judgments upon the Earth; the Execution of which was intrusted to them, and are therefore set out (though they be always ready) after the manner of Men, preparing themselves to execute what God had intrusted them with the Execution of.