Exodus 8:24-27

24The 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.

25Then Pharaoh summoned Moses and Aaron and said, “Go, sacrifice to your God within the land.”

26But 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?

27We must go on a three-day journey into the desert and sacrifice to the Lord our God, just as he is telling us.”