And they did so. Aaron stretched out his hand with his staff and struck the dust of the earth, and there were gnats on man and beast. All the dust of the earth became gnats in all the land of Egypt.
Here is a short account of the plague of lice. It does not appear that any warning was given of it before. Pharaoh's abuse of the respite granted to him might have been a sufficient warning to him to expect another plague: for if the removal of an affliction harden us, and so we lose the benefit of it, we may conclude it goes away...
Commenting on Exodus 8:16-19
And the magicians did so with their enchantments, to bring forth lice,.... They made use of their magical art, and juggling tricks they were masters of, to produce the like sort of creatures, or at least to make such appear, or seem to appear, to the eyes of men: but they could not; God would not suffer them to do it, to impose upon Pharaoh...
PLAGUE OF LICE. (Exo 8:16-19) smite the dust of the land, &c.--Aaron's rod, by the direction of Moses, who was commanded by God, was again raised, and the land was filled with gnats, mosquitoes--that is the proper meaning of the original term.
Commenting on Exodus 8:16-19