Exodus 8:26-27

26But Moses said, ‘It would not be right to do that. The Egyptians do not like our sacrifices of animals. If we offer these sacrifices to the Lord our God, the Egyptians will be angry with us. They will throw stones at us to kill us.

27So we must go on a journey for three days into the desert. We will offer sacrifices to the Lord our God there, as he has told us to do.’