Exodus 4:6-8

Again, the LORD said to him, “Put your hand inside your cloak.” And he put his hand inside his cloak, and when he took it out, behold, his hand was leprous like snow. Then God said, “Put your hand back inside your cloak.” So he put his hand back inside his cloak, and when he took it out, behold, it was restored like the rest of his flesh. “If they will not believe you,” God said, “or listen to the first sign, they may believe the latter sign.