Exodus 7:3

7:3 But I will harden Pharaoh’s heart, and although I will multiply my signs and my wonders in the land of Egypt,

Exodus 11:9

11:9 The Lord said to Moses, “Pharaoh will not listen to you, so that my wonders may be multiplied in the land of Egypt.”

Exodus 4:21

4:21 The Lord said to Moses, “When you go back to Egypt, see that you do before Pharaoh all the wonders I have put under your control. But I will harden his heart and he will not let the people go.

Exodus 7:9

7:9 “When Pharaoh says to you, ‘Do a miracle,’ and you say to Aaron, ‘Take your staff and throw it down before Pharaoh,’ it will become a snake.”

Exodus 11:10

11:10 So Moses and Aaron did all these wonders before Pharaoh, but the Lord hardened Pharaoh’s heart, and he did not release the Israelites from his land.