12 So Moses and Aaron left Pharaoh's palace, and Moses cried out to the Lord about the frogs he had inflicted on Pharaoh. 13 And the Lord did just what Moses had predicted. The frogs in the houses, the courtyards, and the fields all died. 14 The Egyptians piled them into great heaps, and a terrible stench filled the land. 15 But when Pharaoh saw that relief had come, he became stubborn. He refused to listen to Moses and Aaron, just as the Lord had predicted.
16 So the Lord said to Moses, "Tell Aaron, 'Raise your staff and strike the ground. The dust will turn into swarms of gnats throughout the land of Egypt.'" 17 So Moses and Aaron did just as the Lord had commanded them. When Aaron raised his hand and struck the ground with his staff, gnats infested the entire land, covering the Egyptians and their animals. All the dust in the land of Egypt turned into gnats. 18 Pharaoh's magicians tried to do the same thing with their secret arts, but this time they failed. And the gnats covered everyone, people and animals alike. 19 "This is the finger of God!" the magicians exclaimed to Pharaoh. But Pharaoh's heart remained hard. He wouldn't listen to them, just as the Lord had predicted.
Matthew Henry's Commentary on Exodus 8:12-19
Commentary on Exodus 8:1-15
(Read Exodus 8:1-15)
Pharaoh is plagued with frogs; their vast numbers made them sore plagues to the Egyptians. God could have plagued Egypt with lions, or bears, or wolves, or with birds of prey, but he chose to do it by these despicable creatures. God, when he pleases, can arm the smallest parts of the creation against us. He thereby humbled Pharaoh. They should neither eat, nor drink, nor sleep in quiet; but wherever they were, they should be troubled by the frogs. God's curse upon a man will pursue him wherever he goes, and lie heavy upon him whatever he does. Pharaoh gave way under this plague. He promises that he will let the people go. Those who bid defiance to God and prayer, first or last, will be made to see their need of both. But when Pharaoh saw there was respite, he hardened his heart. Till the heart is renewed by the grace of God, the thoughts made by affliction do not abide; the convictions wear off, and the promises that were given are forgotten. Till the state of the air is changed, what thaws in the sun will freeze again in the shade.
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.