21. Else, if you will not let my people go, behold, I will send swarms of flies upon you, and upon your servants, and upon your people, and into your houses: and the houses of the Egyptians shall be full of swarms of flies, and also the ground on which they are.
22. And I will set apart in that day the land of Goshen, in which my people dwell, that no swarms of flies shall be there; to the end you may know that I am the LORD in the midst of the earth.
23. And I will put a division between my people and your people: tomorrow shall this sign be.
24. And the LORD did so; and there came a grievous swarm of flies into the house of Pharaoh, and into his servants' houses, and into all the land of Egypt: the land was corrupted by reason of the swarm of flies.