Exodus 7:11-13

11But Pharaoh called the wise men and sorcerers and magicians of Egypt, and they also did the same things by their magic arts. 12Each one threw down his staff, and it became a serpent. But Aaron’s staff swallowed up the other staffs.

13Still, Pharaoh’s heart was hardened,1 and he would not listen to them, just as the LORD had said.