Exodus 11:7-9

7But among the Israelites not a dog will bark at any person or animal.’ Then you will know that the Lord makes a distinction between Egypt and Israel.

8All these officials of yours will come to me, bowing down before me and saying, ‘Go, you and all the people who follow you!’ After that I will leave.” Then Moses, hot with anger, left Pharaoh.

9The Lord had said to Moses, “Pharaoh will refuse to listen to you—so that my wonders may be multiplied in Egypt.”