Exodus 8:20-22

20And Jehovah said to Moses, Rise up early in the morning, and stand before PharaohH6547 — behold, he will goH935 out to the water — and say to him, ThusH3651 saith Jehovah, Let my people goH935, that they may serve me.

21For, if thou do not let my people go, behold, I will send dog-flies upon thee, and upon thy bondmen, and upon thy people, and into thy houses; and the houses of the Egyptians shall be full of dog-flies, and also the groundH776 on which they are.

22And I will distinguish in that day the land of Goshen, in which my people dwell, that no dog-flies shall be there; that thou mayest know that I Jehovah am in the midst of the land.