Exodus 8:24-26

New Revised Standard Version, Anglicised

²⁴ The Lord did so, and great swarms of flies came into the house of Pharaoh and into his officials’ houses; in all of Egypt the land was ruined because of the flies.

²⁵ Then Pharaoh summoned Moses and Aaron, and said, ‘Go, sacrifice to your God within the land.’ ²⁶ But Moses said, ‘It would not be right to do so; for the sacrifices that we offer to the Lord our God are offensive to the Egyptians. If we offer in the sight of the Egyptians sacrifices that are offensive to them, will they not stone us?