Exodus 8:20-32 - Plague Four: Flies
20 The Lord said to Moses, "Get up early in the morning and position yourself before Pharaoh as he goes out to the water, and tell him, 'Thus says the Lord, "Release my people that they may serve me! 21 If you do not release my people, then I am going to send swarms of flies on you and on your servants and on your people and in your houses. The houses of the Egyptians will be full of flies, and even the ground they stand on. 22 But on that day I will mark off the land of Goshen, where my people are staying, so that no swarms of flies will be there, that you may know that I am the Lord in the midst of this land. 23 I will put a division between my people and your people. This sign will take place tomorrow."'"
24 The Lord did so; a thick swarm of flies came into Pharaoh's house and into the houses of his servants, and throughout the whole land of Egypt the land was ruined because of the swarms of flies. 25 Then Pharaoh summoned Moses and Aaron and said, "Go, sacrifice to your God within the land."
26 But Moses said, "That would not be the right thing to do, for the sacrifices we make to the Lord our God would be an abomination to the Egyptians. If we make sacrifices that are an abomination to the Egyptians right before their eyes, will they not stone us? 27 We must go on a three-day journey into the desert and sacrifice to the Lord our God, just as he is telling us."
28 Pharaoh said, "I will release you so that you may sacrifice to the Lord your God in the desert. Only you must not go very far. Do pray for me."
29 Moses said, "I am going to go out from you and pray to the Lord, and the swarms of flies will go away from Pharaoh, from his servants, and from his people tomorrow. Only do not let Pharaoh deal falsely again by not releasing the people to sacrifice to the Lord." 30 So Moses went out from Pharaoh and prayed to the Lord, 31 and the Lord did as Moses asked -- he removed the swarms of flies from Pharaoh, from his servants, and from his people. Not one remained! 32 But Pharaoh hardened his heart this time also and did not release the people.