Shemot 7:22-24

Orthodox Jewish Bible

²² And the kharetumei Mitzrayim did so with their secret lore: and lev Pharaoh was hardened, neither did he pay heed unto them; as Hashem had said.

²³ And Pharaoh turned and went into his bais, neither did he set his mind to this also.

²⁴ And all the Egyptians dug around the Nile for mayim to drink; they could not drink of the mayim of the Nile.