91 And at the sounding of the fifth angel I saw a star falling from heaven to the earth: and there was given to him the key of the great deep. 2 And he made the great deep open and a smoke went up from it, like the smoke of a great oven; and the sun and the air were made dark because of the smoke. 3 And from the smoke locusts came out on the earth; and power was given them, like the power of scorpions. 4 And they were ordered to do no damage to the grass of the earth, or any green thing, or any tree, but only to such men as have not the mark of God on their brows. 5 And orders were given them not to put them to death, but to give them great pain for five months: and their pain was as the pain from the wound of a scorpion. 6 And in those days men will be hoping for death, and it will not come to them; and they will have a great desire for death, and death will go in flight from them.
Matthew Henry's Commentary on Revelation 9:1-6
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.