And if thou refuse to let them go, behold, I will smite all thy borders with frogs:
All thy borders — All the land that is within thy borders.
 And the river shall bring forth frogs abundantly, which shall go up and come into thine house, and into thy bedchamber, and upon thy bed, and into the house of thy servants, and upon thy people, and into thine ovens, and into thy kneadingtroughs:
The River — Nile. Under which are comprehended all other rivers and waters.
 And Moses said unto Pharaoh, Glory over me: when shall I intreat for thee, and for thy servants, and for thy people, to destroy the frogs from thee and thy houses, that they may remain in the river only?
Glory over me — That is, I yield to thee.
 And he said, To morrow. And he said, Be it according to thy word: that thou mayest know that there is none like unto the LORD our God.
And he said, To-morrow — Why not immediately? Probably he hoped that this night they would go away of themselves, and then he should get clear of the plague, without being obliged either to God or Moses. However, Moses joins issue with him upon it.
Be it according to thy word — It shall be done just when thou wouldst have it done, that thou mayst know, that whatever the magicians pretend to, there is none like unto the Lord our God - None has such a command as he has over all creatures, nor is any so ready to forgive those that humble themselves before him. The great design both of judgments and mercies, is to convince us that there is none like the Lord our God; none so wise, so mighty, so good; no enemy so formidable, no friend so desirable, so valuable.
 But when Pharaoh saw that there was respite, he hardened his heart, and hearkened not unto them; as the LORD had said.
But when Pharaoh saw that there was respite, he hardened his heart — Observe he did it himself, not God, any otherwise than by not hindering.
 And they did so; for Aaron stretched out his hand with his rod, and smote the dust of the earth, and it became lice in man, and in beast; all the dust of the land became lice throughout all the land of Egypt.
The frogs were produced out of the waters, but the lice out of the dust of the earth; for out of any part of the creation God can fetch a scourge wherewith to correct those that rebel against him.
 And the magicians did so with their enchantments to bring forth lice, but they could not: so there were lice upon man, and upon beast.
And the magicians did so — That is, endeavoured to do so.
 Then the magicians said unto Pharaoh, This is the finger of God: and Pharaoh's heart was hardened, and he hearkened not unto them; as the LORD had said.
This is the finger of God — The power of God. The devil's agents, when God permitted them, could do great things; but when he laid an embargo upon them, they could do nothing. The magicians inability in this instance shewed whence they had their ability in the former instances, and that they had no power against Moses but what was given them from above.
But Pharaoh's heart was hardened — By himself and the devil.
 And the LORD said unto Moses, Rise up early in the morning, and stand before Pharaoh; lo, he cometh forth to the water; and say unto him, Thus saith the LORD, Let my people go, that they may serve me.
Rise up early — Those that would bring great things to pass for God and their generation must rise early, and redeem time in the morning. Pharaoh was early up at his superstitious devotions to the river; and shall we be for more sleep, and more slumber, when any service is to be done which would pass well in our account in the great day?
 Else, if thou wilt not let my people go, behold, I will send swarms of flies upon thee, and upon thy servants, and upon thy people, and into thy houses: and the houses of the Egyptians shall be full of swarms of flies, and also the ground whereon they are.
Flies — Or insects of various kinds; not only flies, but gnats, wasps, hornets; and those probably more pernicious than the common ones were.
 And I will sever in that day the land of Goshen, in which my people dwell, that no swarms of flies shall be there; to the end thou mayest know that I am the LORD in the midst of the earth.
Know that I am the Lord in the midst of the earth — In every part of it. Swarms of flies, which seem to us to fly at random, shall be manifestly under the conduct of an intelligent mind. Hither they shall go, saith Moses, and thither they shall come, and the performance is punctual according to this appointment; and both compared amount to a demonstration, that he that said it, and he that did it, was the same, even a being of infinite power and wisdom.
 And I will put a division between my people and thy people: to morrow shall this sign be.
A division — A wall of partition.
 And the LORD did so; and there came a grievous swarm of flies into the house of Pharaoh, and into his servants' houses, and into all the land of Egypt: the land was corrupted by reason of the swarm of flies.
There came a grievous swarm of flies — The prince of the power of the air has gloried in being Beel-zebub, the god of flies; but here it is proved that even in that he is a pretender, and an usurper; for even with swarms of flies God fights against his kingdom and prevails.
 And Moses said, It is not meet so to do; for we shall sacrifice the abomination of the Egyptians to the LORD our God: lo, shall we sacrifice the abomination of the Egyptians before their eyes, and will they not stone us?
The abomination of the Egyptians — That which they abominate to see killed, because they worshipped them as gods.
 We will go three days' journey into the wilderness, and sacrifice to the LORD our God, as he shall command us.
As he shall command us — For he has not yet told us what sacrifices to offer.
 And Pharaoh said, I will let you go, that ye may sacrifice to the LORD your God in the wilderness; only ye shall not go very far away: intreat for me.
Ye shall not go very far away — Not so far but that he might fetch them back again. It is likely he suspected that if once they left Egypt, they would never come back; and therefore when he is forced to consent that they shall go, yet he is not willing they should go out of his reach. See how ready God is to accept sinners submissions. Pharaoh only says, Intreat for me - Moses promises immediately, I will intreat the Lord for thee; and that he might see what the design of the plague was, not to bring him to ruin, but to repentance.
 And Pharaoh hardened his heart at this time also, neither would he let the people go.
But Pharaoh hardened his heart at this time also — Still it is his own act and deed, not God's.