And I will harden Pharaoh's heart, so that he will pursue them; and I will glorify Myself over Pharaoh and over all his army, that the Egyptians may know that I am Jehovah. And they did so.

And the Egyptians shall know that I am Jehovah when I stretch forth My hand upon Egypt and bring out the children of Israel from among them.

Therefore thus says Jehovah: By this you shall know that I am Jehovah. Behold, I will strike the waters in the river with the staff that is in my hand, and they shall be turned to blood.