2 And he opened the pit of the abyss; and there went up a smoke out of the pit, as the smoke of a great furnace; and the sun and the air were darkened by reason of the smoke of the pit. 3 And out of the smoke came forth locusts upon the earth; and power was given them, as the scorpions of the earth have power. 4 And it was said unto them that they should not hurt the grass of the earth, neither any green thing, neither any tree, but only such men as have not the seal of God on their foreheads. 5 And it was given 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 striketh a man. 6 And in those days men shall seek death, and shall in no wise find it; and they shall desire to die, and death fleeth from them. 7 And the shapes of the locusts were like unto horses prepared for war; and upon their heads as it were crowns like unto gold, and their faces were as men's faces. 8 And they had hair as the hair of women, and their teeth were as [teeth] of lions. 9 And they had breastplates, as it were breastplates of iron; and the sound of their wings was as the sound of chariots, of many horses rushing to war. 10 And they have tails like unto scorpions, and stings; and in their tails is their power to hurt men five months. 11 They have over them as king the angel of the abyss: his name in Hebrew is Abaddon, and in the Greek [tongue] he hath the name Apollyon.

Matthew Henry's Commentary on Revelation 9:2-11

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.