Exodus 8:25-29

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

26But Moses said, “That would not be right. The sacrifices we offer the Lord our God would be detestable to the Egyptians. And if we offer sacrifices that are detestable in their eyes, will they not stone us?

27We must take a three-day journey into the wilderness to offer sacrifices to the Lord our God, as he commands us.”

28Pharaoh said, “I will let you go to offer sacrifices to the Lord your God in the wilderness, but you must not go very far. Now pray for me.”

29Moses answered, “As soon as I leave you, I will pray to the Lord, and tomorrow the flies will leave Pharaoh and his officials and his people. Only let Pharaoh be sure that he does not act deceitfully again by not letting the people go to offer sacrifices to the Lord.”