Exodus 7:22-24

Living Bible

²² But then the magicians of Egypt used their secret arts and they, too, turned water into blood; so Pharaoh’s heart remained hard and stubborn, and he wouldn’t listen to Moses and Aaron, just as the Lord had predicted, ²³ and he returned to his palace, unimpressed. ²⁴ Then the Egyptians dug wells along the riverbank to get drinking water, for they couldn’t drink from the river.