Exodus 7:9-10

English Standard Version

Chapter 7

9 “When Pharaoh says to you, ‘Prove yourselves by working a miracle,’ then you shall say to Aaron, ‘Take your staff and cast it down before Pharaoh, that it may become a serpent.’” 10 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.