17 This is what the LORD says: By this you will know that I am the LORD: With the staff that is in my hand I will strike the water of the Nile, and it will be changed into blood.

Read Exodus 7:17 Using Other Translations

Thus saith the LORD, In this thou shalt know that I am the LORD: behold, I will smite with the rod that is in mine hand upon the waters which are in the river, and they shall be turned to blood.
Thus says the LORD, "By this you shall know that I am the LORD: behold, with the staff that is in my hand I will strike the water that is in the Nile, and it shall turn into blood.
So this is what the LORD says: “I will show you that I am the LORD .” Look! I will strike the water of the Nile with this staff in my hand, and the river will turn to blood.