Exodus 4:2-9

2And Jehovah said unto him, What is that in thy hand? And he said, A rod. 3And 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. 4And Jehovah said unto Moses, Put forth thy hand, and take it by the tail: (and he put forth his hand, and laid hold of it, and it became a rod in his hand); 5that they may believe that Jehovah, the God of their fathers, the God of Abraham, the God of Isaac, and the God of Jacob, hath appeared unto thee. 6And Jehovah said furthermore unto him, Put now thy hand into thy bosom. And he put his hand into his bosom: and when he took it out, behold, his hand was leprous, as white as snow. 7And he said, Put thy hand into thy bosom again. (And he put his hand into his bosom again; and when he took it out of his bosom, behold, it was turned again as his other flesh.) 8And it shall come to pass, if they will not believe thee, neither hearken to the voice of the first sign, that they will believe the voice of the latter sign. 9And it shall come to pass, if they will not believe even these two signs, neither hearken unto thy voice, that thou shalt take of the water of the river, and pour it upon the dry land: and the water which thou takest out of the river shall become blood upon the dry land.