Exodus 8:16-19

16Then the Lord said to Moses, “Say to Aaron, ‘Stretch out your staff and strike the dust of the ground, and it will become [biting] gnats (lice) throughout the land of Egypt.’ ”

17They did so; Aaron stretched out his hand with his staff and struck the dust of the earth, and there were [biting] gnats on man and animal. All the dust of the land became gnats through all the land of Egypt.

18The magicians (soothsayer-priests) tried by their secret arts and enchantments to create gnats, but they could not; and there were gnats on man and animal.

19Then the magicians said to Pharaoh, “This is the [supernatural] finger of God.” But Pharaoh’s heart was hardened and he would not listen to them, just as the Lord had said.