Exodus 7:15-18

15Go to Pharaoh in the morning when he goes to the river. Wait for him by the edge of the river. Then take in your hand the stick that became a snake.

16Then say to Pharaoh, “The Lord, the God of the Israelites, has sent me to you to say, ‘Let my people go, so that they may worship me in the desert.’ But until now, you have not listened to my message.

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.” ’