Exodus 7:13, 14-18, 22-25

Yet Pharaoh was as stubborn as ever—he wouldn’t listen to them, just as GOD had said.

GOD said to Moses: “Pharaoh is a stubborn man. He refuses to release the people. First thing in the morning, go and meet Pharaoh as he goes down to the river. At the shore of the Nile take the staff that turned into a snake and say to him, ‘GOD, the God of the Hebrews, sent me to you with this message, “Release my people so that they can worship me in the wilderness.” So far you haven’t listened. This is how you’ll know that I am GOD. I am going to take this staff that I’m holding and strike this Nile River water: The water will turn to blood; the fish in the Nile will die; the Nile will stink; and the Egyptians won’t be able to drink the Nile water.’”

But the magicians of Egypt did the same thing with their incantations. Still Pharaoh remained stubborn. He wouldn’t listen to them as GOD had said. He spun around and went home, never giving it a second thought. But all the Egyptians had to dig inland from the river for water because they couldn’t drink the Nile water. Seven days went by after GOD had struck the Nile.