The rod was probably in the form of a walking-stick, but it could also have been used as a shepherd’s staff or even a weapon. We are not specifically told. Aaron’s rod is first mentioned by name in Exodus 7:9-12 [9] When Pharaoh shall speak unto you, saying, Shew a miracle for you: then thou shalt say unto Aaron, Take thy rod, and cast it before Pharaoh, and it shall become a serpent. [10] And Moses and Aaron went in unto Pharaoh, and they did so as the LORD had commanded: and Aaron cast down his rod before Pharaoh, and before his servants, and it became a serpent. [11] Then Pharaoh also called the wise men and the sorcerers: now the magicians of Egypt, they also did in like manner with their enchantments. [12] For they cast down every man his rod, and they became serpents: but Aaron's rod swallowed up their rods.
See All..., when Moses commanded him to cast down his rod before Pharaoh. It became a serpent and then swallowed up the magicians’ rods that had become serpents. This was the initial sign that God had given to Moses to verify to the Israelites that he was sent from God (Exodus 4:1-4 [1] And Moses answered and said, But, behold, they will not believe me, nor hearken unto my voice: for they will say, The LORD hath not appeared unto thee. [2] And the LORD said unto him, What is that in thine hand? And he said, A rod. [3] And he said, Cast it on the ground. And he cast it on the ground, and it became a serpent; and Moses fled from before it. [4] And the LORD said unto Moses, Put forth thine hand, and take it by the tail. And he put forth his hand, and caught it, and it became a rod in his hand:
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