Exodus 7:11-13

Then Pharaoh also called for the wise men and the sorcerers: and they also, the magicians of Egypt, did in like manner with their enchantments. For they cast down every man his rod, and they became serpents: but Aaron’s rod swallowed up their rods. And Pharaoh’s heart was hardened, and he hearkened not unto them; as Jehovah had spoken.