Exodus 7:8-10

Darby Translation

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.

¹⁰ And Moses and Aaron went in to Pharaoh, and did so, as Jehovah had commanded; and Aaron cast down his staff before Pharaoh, and before his bondmen, and it became a serpent.