Exodus 8:20-22

20And Jehovah said unto Moses, Rise up early in the morning, and stand before PharaohH6547; lo, he cometh forth to the water; and say unto him, ThusH3651 saith Jehovah, Let my people goH935, that they may serve me. 21Else, if thou wilt not let my people go, behold, I will send swarms of flies upon thee, and upon thy servants, and upon thy people, and into thy houses: and the houses of the Egyptians shall be full of swarms of flies, and also the groundH776 whereon they are. 22And 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 thou mayest know that I am Jehovah in the midst of the earth.