Matthew Poole and continuators on Revelation 9:13

13 And the sixth angel sounded, and I heard a voice from the four horns of the golden altar which is before God .

That is, from God, I heard him give a Command, which Voice is said to have proceeded from the Golden Altar (in allusion to Exod. 30.3.) because there God received the Prayers of his People; and this Voice proceeding from that place, might signify the following Judgment to come, in answer to the Prayers of his servants Souls from thence crying to him for Vengeance. See chap. 6.9, 10.