91 And the fifth angel sounded [his] trumpet: and I saw a star out of the heaven fallen to the earth; and there was given to it the key of the pit of the abyss. 2 And it opened the pit of the abyss; and there went up smoke out of the pit as [the] smoke of a great furnace; and the sun and the air were darkened with the smoke of the pit. 3 And out of the smoke came forth locusts on the earth, and power was given to them as the scorpions of the earth have power; 4 and it was said to them, that they should not injure the grass of the earth, nor any green thing, nor any tree, but the men who have not the seal of God on their foreheads: 5 and it was given to them that they should not kill them, but that they should be tormented five months; and their torment [was] as [the] torment of a scorpion when it strikes a man. 6 And in those days shall men seek death, and shall in no way find it; and shall desire to die, and death flees from them. 7 And the likenesses of the locusts [were] like to horses prepared for war; and upon their heads as crowns like gold, and their faces as faces of men; 8 and they had hair as women's hair, and their teeth were as of lions, 9 and they had breastplates as breastplates of iron, and the sound of their wings [was] as the sound of chariots of many horses running to war; 10 and they have tails like scorpions, and stings; and their power [was] in their tails to hurt men five months.
Matthew Henry's Commentary on Revelation 9:1-10
Commentary on Revelation 9:1-12
(Read Revelation 9:1-12)
Upon sounding the fifth trumpet, a star fell from heaven to the earth. Having ceased to be a minister of Christ, he who is represented by this star becomes the minister of the devil; and lets loose the powers of hell against the churches of Christ. On the opening of the bottomless pit, there arose a great smoke. The devil carries on his designs by blinding the eyes of men, by putting out light and knowledge, and promoting ignorance and error. Out of this smoke there came a swarm of locusts, emblems of the devil's agents, who promote superstition, idolatry, error, and cruelty. The trees and the grass, the true believers, whether young or more advanced, should be untouched. But a secret poison and infection in the soul, should rob many others of purity, and afterwards of peace. The locusts had no power to hurt those who had the seal of God. God's all-powerful, distinguishing grace will keep his people from total and final apostacy. The power is limited to a short season; but it would be very sharp. In such events the faithful share the common calamity, but from the pestilence of error they might and would be safe. We collect from Scripture, that such errors were to try and prove the Christians, 1 Corinthians 11:19. And early writers plainly refer this to the first great host of corrupters who overspread the Christian church.