Exodus 7:7-9

Darby Translation

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

⁸ And Jehovah spoke to Moses and to Aaron, saying,

⁹ When Pharaoh shall speak to you, saying, Do a miracle for yourselves,—then thou shalt say unto Aaron, Take thy staff and cast [it] before Pharaoh—it will become a serpent.