Exodus 7:19-22

19Then the Lord said to Moses, “Tell Aaron, ‘Take your staff and stretch out your hand over Egypt’s waters – over their rivers, over their canals, over their ponds, and over all their reservoirs – so that it becomes blood.’ There will be blood everywhere in the land of Egypt, even in wooden and stone containers.”

20Moses and Aaron did so, just as the Lord had commanded. Moses raised the staff and struck the water that was in the Nile right before the eyes of Pharaoh and his servants, and all the water that was in the Nile was turned to blood.

21When the fish that were in the Nile died, the Nile began to stink, so that the Egyptians could not drink water from the Nile. There was blood everywhere in the land of Egypt!

22But the magicians of Egypt did the same by their secret arts, and so Pharaoh’s heart remained hard, and he refused to listen to Moses and Aaron – just as the Lord had predicted.