Exodus 4:6-8

6In addition the Lord said to him, “Put your hand inside your cloak.” So he put his hand inside his cloak, and when he took it out, his hand was diseased, resembling snow.

7“Put your hand back inside your cloak,” he said. So he put his hand back inside his cloak, and when he took it out, it had again become like the rest of his skin.

8“If they will not believe you and will not respond to the evidence of the first sign, they may believe the evidence of the second sign.