Exodus 7:7-13

And Moses was fourscore years old, and Aaron fourscore and three years old, when they spake unto Pharaoh. And Jehovah spake unto Moses and unto Aaron, saying, When Pharaoh shall speak unto you, saying, Show a wonder for you; then thou shalt say unto Aaron, Take thy rod, and cast it down before Pharaoh, that it become a serpent. And Moses and Aaron went in unto Pharaoh, and they did so, as Jehovah had commanded: and Aaron cast down his rod before Pharaoh and before his servants, and it became a serpent. Then Pharaoh also called for the wise men and the sorcerers: and they also, the magicians of Egypt, did in like manner with their enchantments. For they cast down every man his rod, and they became serpents: but Aaron’s rod swallowed up their rods. And Pharaoh’s heart was hardened, and he hearkened not unto them; as Jehovah had spoken.