14 Then the Lord said to Moses: "The heart of Pharaoh has been hardened; he is not willing to release the people.
15 Go to him in the morning; behold, he will go out to the waters. And you will stand to meet him above the bank of the river. And you will take, in your hand, the staff that was turned into a serpent.
16 And you will say to him: 'The Lord God of the Hebrews sent me to you, saying: Release my people in order to sacrifice to me in the desert. And even until the present time, you were not willing to listen.
17 Therefore, thus says the Lord: In this you will know that I am the Lord. Behold, I will strike, with the staff that is in my hand, the water of the river, and it will be turned into blood.
18 Also, the fishes that are in the river will die, and the waters will be polluted, and the Egyptians will be afflicted when they drink the water of the river.' "
19 The Lord also said to Moses: "Say to Aaron: 'Take your staff; and extend your hand over the waters of Egypt, and over their rivers and streams and marshes and all the pools of waters, so that they may be turned into blood. And let there be blood throughout all the land of Egypt, as much in vessels of wood as in those of stone.' "
20 And Moses and Aaron did just as the Lord had instructed. And lifting up the staff, he struck the water of the river in the sight of Pharaoh and his servants. And it was turned into blood.