16 Then the Lord said to Moses, "Say to Aaron, "Stretch out your staff and strike the dust of the earth, so that it may become gnats throughout the whole land of Egypt.' " 17 And they did so; Aaron stretched out his hand with his staff and struck the dust of the earth, and gnats came on humans and animals alike; all the dust of the earth turned into gnats throughout the whole land of Egypt. 18 The magicians tried to produce gnats by their secret arts, but they could not. There were gnats on both humans and animals. 19 And the magicians said to Pharaoh, "This is the finger of God!" But Pharaoh's heart was hardened, and he would not listen to them, just as the Lord had said.
20 Then the Lord said to Moses, "Rise early in the morning and present yourself before Pharaoh, as he goes out to the water, and say to him, "Thus says the Lord: Let my people go, so that they may worship me. 21 For if you will not let my people go, I will send swarms of flies on you, your officials, and your people, and into your houses; and the houses of the Egyptians shall be filled with swarms of flies; so also the land where they live. 22 But on that day I will set apart the land of Goshen, where my people live, so that no swarms of flies shall be there, that you may know that I the Lord am in this land. 23 Thus I will make a distinction between my people and your people. This sign shall appear tomorrow.' " 24 The Lord did so, and great swarms of flies came into the house of Pharaoh and into his officials' houses; in all of Egypt the land was ruined because of the flies. 25 Then Pharaoh summoned Moses and Aaron, and said, "Go, sacrifice to your God within the land." 26 But Moses said, "It would not be right to do so; for the sacrifices that we offer to the Lord our God are offensive to the Egyptians. If we offer in the sight of the Egyptians sacrifices that are offensive to them, will they not stone us? 27 We must go a three days' journey into the wilderness and sacrifice to the Lord our God as he commands us." 28 So Pharaoh said, "I will let you go to sacrifice to the Lord your God in the wilderness, provided you do not go very far away. Pray for me." 29 Then Moses said, "As soon as I leave you, I will pray to the Lord that the swarms of flies may depart tomorrow from Pharaoh, from his officials, and from his people; only do not let Pharaoh again deal falsely by not letting the people go to sacrifice to the Lord." 30 So Moses went out from Pharaoh and prayed to the Lord. 31 And the Lord did as Moses asked: he removed the swarms of flies from Pharaoh, from his officials, and from his people; not one remained. 32 But Pharaoh hardened his heart this time also, and would not let the people go.
Matthew Henry's Commentary on Exodus 8:16-32
Commentary on Exodus 8:16-19
(Read Exodus 8:16-19)
These lice were produced out of the dust of the earth; out of any part of the creation God can fetch a scourge, with which to correct those who rebel against him. Even the dust of the earth obeys him. These lice were very troublesome, as well as disgraceful to the Egyptians, whose priests were obliged to take much pains that no vermin ever should be found about them. All the plagues inflicted on the Egyptians, had reference to their national crimes, or were rendered particularly severe by their customs. The magicians attempted to imitate it, but they could not. It forced them to confess, This is the finger of God! The check and restraint put upon us, must needs be from a Divine power. Sooner or later God will force even his enemies to acknowledge his own power. Pharaoh, notwithstanding this, was more and more obstinate.
Commentary on Exodus 8:20-32
(Read Exodus 8:20-32)
Pharaoh was early at his false devotions to the river; and shall we be for more sleep and more slumber, when any service to the Lord is to be done? The Egyptians and the Hebrews were to be marked in the plague of flies. The Lord knows them that are his, and will make it appear, perhaps in this world, certainly in the other, that he has set them apart for himself. Pharaoh unwillingly entered into a treaty with Moses and Aaron. He is content they should sacrifice to their God, provided they would do it in the land of Egypt. But it would be an abomination to God, should they offer the Egyptian sacrifices; and it would be an abomination to the Egyptians, should they offer to God the objects of the worship of the Egyptians, namely, their calves or oxen. Those who would offer acceptable sacrifice to God, must separate themselves from the wicked and profane. They must also retire from the world. Israel cannot keep the feast of the Lord, either among the brick-kilns or among the flesh-pots of Egypt. And they must sacrifice as God shall command, not otherwise. Though they were in slavery to Pharaoh, yet they must obey God's commands. Pharaoh consents for them to go into the wilderness, provided they do not go so far but that he might fetch them back again. Thus, some sinners, in a pang of conviction, part with their sins, yet are loth they should go very far away; for when the fright is over, they will turn to them again. Moses promised the removal of this plague. But let not Pharaoh deal deceitfully any more. Be not deceived; God is not mocked: if we think to cheat God by a sham repentance and a false surrender of ourselves to him, we shall put a fatal cheat upon our own souls. Pharaoh returned to his hardness. Reigning lusts break through the strongest bonds, and make men presume and go from their word. Many seem in earnest, but there is some reserve, some beloved, secret sin. They are unwilling to look upon themselves as in danger of everlasting misery. They will refrain from other sins; they do much, give much, and even punish themselves much. They will leave it off sometimes, and, as it were, let their sin depart a little way; but will not make up their minds to part with all and follow Christ, bearing the cross. Rather than that, they venture all. They are sorrowful, but depart from Christ, determined to keep the world at present, and they hope for some future season, when salvation may be had without such costly sacrifices; but, at length, the poor sinner is driven away in his wickedness, and left without hope to lament his folly.