Exodus 4:2-6

The Lord said to him, “What is that in your hand?” And he said, “A staff.”

Then He said, “Throw it on the ground.” So he threw it on the ground, and it turned into a serpent; and Moses fled from it.

But the Lord said to Moses, “Reach out with your hand and grasp it by its tail”—so he reached out with his hand and caught it, and it turned into a staff in his hand—

“so that they may believe that the Lord, the God of their fathers, the God of Abraham, the God of Isaac, and the God of Jacob, has appeared to you.”

The Lord furthermore said to him, “Now put your hand inside the fold of your robe.” So he put his hand inside the fold, and when he took it out, behold, his hand was leprous like snow.