Exodus 8:25-27

Then Pharaoh called Moses and Aaron and said, “Go, sacrifice to your God within the land.” But Moses said, “It would not be right to do so, for the offerings we shall sacrifice to the LORD our God are an abomination to the Egyptians. If we sacrifice offerings abominable to the Egyptians before their eyes, will they not stone us? We must go three days’ journey into the wilderness and sacrifice to the LORD our God as he tells us.”