Exodus 8:25-29

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.”

28Pharaoh 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.”

29Moses 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.”