Exodus 7:22-24

Complete Jewish Bible

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. ²⁴ All the Egyptians dug around the river for water to drink, because they couldn’t drink the river water.