²¹ If you will not let my people go, I will send swarms of flies on you, your officials, your people, and your houses. The homes of the Egyptians will be filled with flies, and even the ground outside will be covered with them. ²² But on that day I will treat the region of Goshen differently. That is where my people live. There won’t be any flies there. This way you will know that I, Yahweh, am here in this land. ²³ I will distinguish between my people and yours. This miraculous sign will happen tomorrow.’”