So Aaron stretched out his hand over the waters of Egypt, and the frogs came up and covered the land of Egypt.
Pharaoh is here first threatened and then plagued with frogs, as afterwards, in this chapter, with lice and flies, little despicable inconsiderable animals, and yet by their vast numbers rendered sore plagues to the Egyptians. God could have plagued them with lions, or bears, or wolves, or with vultures or other birds of prey; but he chose to do it by these contemptible instruments. 1.
Commenting on Exodus 8:1-15
And the magicians did so with their enchantments, &c. By their secret wiles and juggling tricks: and brought up frogs upon the land of Egypt, that is, some few, as a proof of their art and skill, and to show that Moses and Aaron did but what they could do; but what they did either were only in appearance, deceiving the sight of Pharaoh and...
And Aaron stretched out his hand over the waters of Egypt; and the frogs came up, and covered the land of Egypt. (b) But Goshen, where God's people dwelt, was excepted.