Shemot 7:23-25

Orthodox Jewish Bible

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.

²⁵ And seven days came and went, after Hashem had struck the Nile.