Exodus 4:6

3 He said, "Throw it on the ground." He threw it on the ground, and it became a snake; and Moses ran away from it.

4 Yahweh said to Moses, "Put forth your hand, and take it by the tail." He put forth his hand, and laid hold of it, and it became a rod in his hand.

5 "That they may believe that Yahweh, the God of their fathers, the God of Abraham, the God of Isaac, and the God of Jacob, has appeared to you."

6 Yahweh said furthermore to him, "Now put your hand inside your cloak." He put his hand inside his cloak, and when he took it out, behold, his hand was leprous, as white as snow.

7 He said, "Put your hand inside your cloak again." He put his hand inside his cloak again, and when he took it out of his cloak, behold, it had turned again as his other flesh.

8 "It will happen, if they will neither believe you nor listen to the voice of the first sign, that they will believe the voice of the latter sign.

9 It will happen, if they will not believe even these two signs, neither listen to your voice, that you shall take of the water of the river, and pour it on the dry land. The water which you take out of the river will become blood on the dry land."