2 If you refuse to let them go, I will send a plague of frogs across your entire land. 3 The Nile River will swarm with frogs. They will come up out of the river and into your palace, even into your bedroom and onto your bed! They will enter the houses of your officials and your people. They will even jump into your ovens and your kneading bowls. 4 Frogs will jump on you, your people, and all your officials.'" 5 Then the Lord said to Moses, "Tell Aaron, 'Raise the staff in your hand over all the rivers, canals, and ponds of Egypt, and bring up frogs over all the land.'" 6 So Aaron raised his hand over the waters of Egypt, and frogs came up and covered the whole land! 7 But the magicians were able to do the same thing with their magic. They, too, caused frogs to come up on the land of Egypt.
Matthew Henry's Commentary on Exodus 8:2-7
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.