Exodus 7:8

4 Pharaoh will not listen to you. Then I will lay My hand on Egypt, and by mighty acts of judgment I will bring the divisions of My people the Israelites out of the land of Egypt.

5 And the Egyptians will know that I am the LORD, when I stretch out My hand against Egypt and bring the Israelites out from among them.”

6 So Moses and Aaron did just as the LORD had commanded them.

7 Moses was eighty years old and Aaron was eighty-three when they spoke to Pharaoh.

8 The LORD said to Moses and Aaron,

9 “When Pharaoh tells you, ‘Perform a miracle,’ you are to say to Aaron, ‘Take your staff and throw it down before Pharaoh,’ and it will become a serpent.”

10 So Moses and Aaron went to Pharaoh and did just as the LORD had commanded. Aaron threw his staff down before Pharaoh and his officials, and it became a serpent.

11 But Pharaoh called the wise men and sorcerers and magicians of Egypt, and they also did the same things by their magic arts.

12 Each one threw down his staff, and it became a serpent. But Aaron’s staff swallowed up the other staffs.

Read all of Exodus 7