Exodus 7:21-23

Complete Jewish Bible

²¹ The fish in the river died, and the river stank so badly that the Egyptians couldn’t drink its water. There was blood throughout all the land of Egypt.

²² But the magicians of Egypt did the same with their secret arts, so that Pharaoh was made hardhearted and didn’t listen to them, as Adonai had said would happen. ²³ Pharaoh just turned and went back to his palace, without taking any of this to heart.