Exodus 7:8-13 NIV

[8] The LORD said to Moses and Aaron, [9] “When Pharaoh says to you, ‘Perform a miracle,’ then say to Aaron, ‘Take your staff and throw it down before Pharaoh,’ and it will become a snake.” [10] So Moses and Aaron went to Pharaoh and did just as the LORD commanded. Aaron threw his staff down in front of Pharaoh and his officials, and it became a snake. [11] Pharaoh then summoned wise men and sorcerers, and the Egyptian magicians also did the same things by their secret arts: [12] Each one threw down his staff and it became a snake. But Aaron’s staff swallowed up their staffs. [13] Yet Pharaoh’s heart became hard and he would not listen to them, just as the LORD had said.