Exodus 7:7-13

Now Moses was eighty years old and Aaron eighty-three years old when they spoke to Pharaoh. Now the LORD said to Moses and Aaron, “When Pharaoh says to you, ‘Work a miracle [to prove your authority],’ then you say to Aaron, ‘Take your staff and throw it down before Pharaoh, so that it may become a serpent.’ ” So Moses and Aaron came to Pharaoh, and did just as the LORD had commanded; Aaron threw down his staff before Pharaoh and his servants, and it became a serpent. Then Pharaoh called for the wise men [skilled in magic and omens] and the sorcerers [skilled in witchcraft], and they also, these magicians (soothsayer-priests) of Egypt, did the same with their secret arts and enchantments. For every man threw down his staff and they turned into serpents; but Aaron’s staff swallowed up their staffs. Yet Pharaoh’s heart was hardened and he would not listen to them, just as the LORD had said.