Exodus 7:17-21

¹⁷Thus says the LORD, "By this you shall know that I am the LORD: behold, I will strike the water that is in the Nile with the rod that is in my hand, and it shall be turned to blood, ¹⁸and the fish in the Nile shall die, and the Nile shall become foul, and the Egyptians will loathe to drink water from the Nile."'" ¹⁹And the LORD said to Moses, "Say to Aaron, `Take your rod and stretch out your hand over the waters of Egypt, over their rivers, their canals, and their ponds, and all their pools of water, that they may become blood; and there shall be blood throughout all the land of Egypt, both in vessels of wood and in vessels of stone.'"

²⁰Moses and Aaron did as the LORD commanded; in the sight of Pharaoh and in the sight of his servants, he lifted up the rod and struck the water that was in the Nile, and all the water that was in the Nile turned to blood. ²¹And the fish in the Nile died; and the Nile became foul, so that the Egyptians could not drink water from the Nile; and there was blood throughout all the land of Egypt.