Exodus 4:8

4 “Stretch out your hand and grab it by the tail,” the LORD said to Moses, who reached out his hand and caught the snake, and it turned back into a staff in his hand.

5 “This is 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.”

6 Furthermore, the LORD said to Moses, “Put your hand inside your cloak.” So he put his hand inside his cloak, and when he took it out, his hand was leprous, white as snow.

7 “Put your hand back inside your cloak,” said the LORD. So Moses put his hand back inside his cloak, and when he took it out, it was restored, like the rest of his skin.

8 And the LORD said, “If they refuse to believe you or heed the witness of the first sign, they may believe that of the second.

9 But if they do not believe even these two signs or listen to your voice, take some water from the Nile and pour it on the dry ground. Then the water you take from the Nile will become blood on the ground.”

10 “Please, Lord,” Moses replied, “I have never been eloquent, neither in the past nor since You have spoken to Your servant, for I am slow of speech and tongue.”

11 And the LORD said to him, “Who gave man his mouth? Or who makes the mute or the deaf, the sighted or the blind? Is it not I, the LORD?

12 Now go! I will help you as you speak, and I will teach you what to say.”

Read all of Exodus 4