Exodus 7:10-15

ISV(i) 10 So Moses and Aaron went in to Pharaoh and did what the LORD had commanded them. Aaron threw his staff in front of Pharaoh and his officials, and it became a serpent. 11 Then Pharaoh also called for the wise men and sorcerers, and they—along with the Egyptian magicians—did the same thing with their secret arts. 12 So each one threw down his staff and it became a serpent, but Aaron’s staff swallowed up their staffs. 13 Yet Pharaoh’s heart was stubborn and he did not listen to them, just as the LORD had said would happen.
14 Water is Turned into BloodThen the LORD told Moses, “Pharaoh’s heart is hard. He has refused to let the people go. 15 Go to Pharaoh in the morning as he’s going down to the water. Stand on the bank of the Nile River and meet him. Be sure to take with you the staff that was turned into a snake.