Exodus 4:2-9

² And the Lord said to him, What is that in your hand? And he said, A rod. ³ And he said, Put it down on the earth. And he put it down on the earth and it became a snake; and Moses went running from it. ⁴ And the Lord said to Moses, Put out your hand and take it by the tail: (and he put out his hand and took a grip of it and it became a rod in his hand:) ⁵ So that they may be certain that the Lord, the God of their fathers, the God of Abraham, of Isaac, and of Jacob, has been seen by you. ⁶ Then the Lord said to him again, Put your hand inside your clothing. And he put his hand inside his robe: and when he took it out it was like the hand of a leper, as white as snow. ⁷ And he said, Put your hand inside your robe again. (And he put his hand into his robe again, and when he took it out he saw that it had become like his other flesh.) ⁸ And if they do not have faith in you or give ear to the voice of the first sign, they will have faith in the second sign. ⁹ And if they have no faith even in these two signs and will not give ear to your voice, then you are to take the water of the Nile and put it on the dry land: and the water you take out of the river will become blood on the dry land.