Exodus 8:20-24

20Then the Lord said to Moses, “Early in the morning, stand in Pharaoh’s way when he’s going to the Nile. Say to him, ‘This is what the Lord says: Let my people go to worship me.

21If you will not let my people go, I will send swarms of flies on you, your officials, your people, and your houses. The homes of the Egyptians will be filled with flies, and even the ground outside will be covered with them.

22But on that day I will treat the region of Goshen differently. That is where my people live. There won’t be any flies there. This way you will know that I, the Lord, am here in this land.

23I will distinguish between my people and yours. This miraculous sign will happen tomorrow.’ ”

24The Lord did what he said. Dense swarms of flies came into Pharaoh’s palace and into the houses of his officials. All over Egypt the flies were ruining everything.