Exodus 7:10-14

So Moses and Aaron came to Pharaoh, and so they did, just as the Lord had commanded; and Aaron threw his staff down before Pharaoh and his servants, and it turned into a serpent.

Then Pharaoh also called for the wise men and the sorcerers, and they too, the soothsayer priests of Egypt, did the same with their secret arts.

For each one threw down his staff, and they turned into serpents. But Aaron’s staff swallowed their staffs.

Yet Pharaoh’s heart was hardened, and he did not listen to them, just as the Lord had said. Water Turned into Blood

Then the Lord said to Moses, “Pharaoh’s heart is stubborn; he refuses to let the people go.