Exodus 7:17-21

17So this is what the Lord says: In this way, you will know that I am the Lord. Look! I will hit the water in the Nile river with the stick that is in my hand. Then the water will become blood.

18The fish in the river will die, and the river will have a very bad smell. Then the Egyptians will not be able to drink the water from the Nile river.” ’

19Then the Lord said to Moses, ‘Say to Aaron, “Take your stick. Lift up your hand over the waters of Egypt. Lift your stick up over their rivers and their streams. Lift it up over their lakes and pools of water. Do that so that all the water becomes blood.” There will be blood in every part of Egypt. There will even be blood in their buckets and bowls.’

20Moses and Aaron obeyed the command of the Lord. Aaron lifted up the stick in front of Pharaoh and his servants. He hit the water in the Nile river with the stick. Then all the water in the river became blood.

21The fish in the river died. The river had such a bad smell that the Egyptians could not drink its water. There was blood in every part of Egypt.