Exodus 7:7 ASV

⁵  And the Egyptians shall know that I am Jehovah, when I stretch forth my hand upon Egypt, and bring out the children of Israel from among them.

⁶  And Moses and Aaron did so; as Jehovah commanded them, so did they.

⁷  And Moses was fourscore years old, and Aaron fourscore and three years old, when they spake unto Pharaoh.

⁸  And Jehovah spake unto Moses and unto Aaron, saying,

⁹  When Pharaoh shall speak unto you, saying, Show a wonder for you; then thou shalt say unto Aaron, Take thy rod, and cast it down before Pharaoh, that it become a serpent.