But I will harden Pharaoh's heart, and though I multiply my signs and wonders in the land of Egypt,
Pharaoh will not listen to you; then I will lay my hand upon Egypt and bring forth my hosts, my people the sons of Israel, out of the land of Egypt by great acts of judgment.
And the Egyptians shall know that I am the LORD, when I stretch forth my hand upon Egypt and bring out the people of Israel from among them."
And Moses and Aaron did so; they did as the LORD commanded them.
Now Moses was eighty years old, and Aaron eighty-three years old, when they spoke to Pharaoh.
And the LORD said to Moses and Aaron,
"When Pharaoh says to you, 'Prove yourselves by working a miracle,' then you shall say to Aaron, 'Take your rod and cast it down before Pharaoh, that it may become a serpent.'"
So Moses and Aaron went to Pharaoh and did as the LORD commanded; Aaron cast down his rod before Pharaoh and his servants, and it became a serpent.
Then Pharaoh summoned the wise men and the sorcerers; and they also, the magicians of Egypt, did the same by their secret arts.
For every man cast down his rod, and they became serpents. But Aaron's rod swallowed up their rods.
Still Pharaoh's heart was hardened, and he would not listen to them; as the LORD had said.
Revised Standard Version of the Bible, copyright 1952 [2nd edition, 1971] by the Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved. (Revised Standard Version - Holy Bible)