Exodus 7:17

7:17 Thus says Yahweh, "In this you shall know that I am Yahweh. Behold, I will strike with the rod that is in my hand on the waters which are in the river, and they shall be turned to blood.
-World English Bible

Other Translation

7:17 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.
-King James Version