Exodus 7:22

²⁰And Moses and Aaron did so, as the LORD commanded; and he lifted up the rod, and smote the waters that were in the river, in the sight of Pharaoh, and in the sight of his servants; and all the waters that were in the river were turned to blood.

²¹And the fish that was in the river died; and the river stank, and the Egyptians could not drink of the water of the river; and there was blood throughout all the land of Egypt.

— Exodus 7:22 —

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

²⁴And all the Egyptians digged round about the river for water to drink; for they could not drink of the water of the river.