Exodus 7:20-21

Darby Translation

²⁰ And Moses and Aaron did so, as Jehovah had commanded; and he lifted up the staff, and smote the waters that were in the river before the eyes of Pharaoh, and before the eyes of his bondmen; and all the waters that were in the river were turned into blood.

²¹ And the fish that was in the river died; and the river stank, and the Egyptians could not drink the water of the river; and the blood was throughout the land of Egypt.