21 But if you will not let my people go, then I will send swarms of fliesC against you, your officials, your people, and your houses. The Egyptians’ houses will swarm with flies, and so will the land where they live.D 22 But on that day I will give special treatment to the land of Goshen, where my people are living;f no flies will be there. This way you will know that I, the Lord, am in the land. 23 I will make a distinctionE between my people and your people. This sign will take place tomorrow.”