[21] Else, if thou wilt not let my people go, swarms of flies upon thee, and upon thy servants, and upon thy people, and into thy houses: shall be full of swarms of flies, and also the ground whereon they are. [22] And I will sever in that day the land of Goshen, in which my people dwell, that no swarms of flies shall be there; to the end thou mayest know that I am the LORD in the midst of the earth. [23] And I will put a division between my people to morrow shall this sign [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