Exodus 8:16-20 New Revised Standard Version (NRSV)
The Third Plague: Gnats
16 Then the Lord said to Moses, “Say to Aaron, ‘Stretch out your staff and strike the dust of the earth, so that it may become gnats throughout the whole land of Egypt.’” 17 And they did so; Aaron stretched out his hand with his staff and struck the dust of the earth, and gnats came on humans and animals alike; all the dust of the earth turned into gnats throughout the whole land of Egypt. 18 The magicians tried to produce gnats by their secret arts, but they could not. There were gnats on both humans and animals. 19 And the magicians said to Pharaoh, “This is the finger of God!” But Pharaoh’s heart was hardened, and he would not listen to them, just as the Lord had said.
The Fourth Plague: Flies
20 Then the Lord said to Moses, “Rise early in the morning and present yourself before Pharaoh, as he goes out to the water, and say to him, ‘Thus says the Lord: Let my people go, so that they may worship me.