So Moses and Aaron went to Pharaoh and did just as the LORD commanded.  Aaron cast down his staff before Pharaoh and his servants, and it became a serpent.  Then Pharaoh summoned the wise men and the sorcerers, and they, the magicians of Egypt, also did the same by their secret arts. – Exodus 7:10-11

Moses and Aaron did as the LORD commanded.  In the sight of Pharaoh and in the sight of his servants he lifted up the staff and struck the water in the Nile, and all the water…