Exodus 8:24-27

24Then the Lord did so. And there came heavy and oppressive swarms of [bloodsucking] insects into the house of Pharaoh and his servants’ houses; in all the land of Egypt the land was corrupted and ruined because of the [great invasion of] insects.

25Then Pharaoh called for Moses and Aaron and said, “Go, sacrifice to your God [here] in the land [of Egypt].”

26But Moses said, “It is not right [or even possible] to do that, for we will sacrifice to the Lord our God what is repulsive and unacceptable to the Egyptians [that is, animals that the Egyptians consider sacred]. If we sacrifice what is repulsive and unacceptable to the Egyptians, will they not riot and stone us?

27We must go a three days’ journey into the wilderness and sacrifice to the Lord our God as He commands us.”