3 But I will harden Pharaoh’s heart, and though I multiply my signs and wonders in the land of Egypt,
4 Pharaoh will not listen to you. Then I will lay my hand on Egypt and bring my hosts, my people the children of Israel, out of the land of Egypt by great acts of judgment.
5 The Egyptians shall know that I am the Lord, when I stretch out my hand against Egypt and bring out the people of Israel from among them.”
6 Moses and Aaron did so; they did just as the Lord commanded them.
7 Now Moses was eighty years old, and Aaron eighty-three years old, when they spoke to Pharaoh.
8 Then the Lord said to Moses and Aaron,
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.’”