Exodus 8:24-27

24And the Lord did this. Dense swarms of flies poured into Pharaoh’s palace and into the houses of his officials; throughout Egypt the land was ruined by the flies.

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.”