Exodus 11:7-9

7But against all the Israelites, whether people or animals, not even a dog will snarl, so that you may know that the Lord makes a distinction between Egypt and Israel.

8All these officials of yours will come down to me and bow before me, saying: Get out, you and all the people who follow you. After that, I will get out.” And he went out from Pharaoh’s presence fiercely angry.

9The Lord said to Moses, “Pharaoh will not listen to you, so that my wonders may be multiplied in the land of Egypt.”