Exodus 4:1-9

Then Moses answered [the LORD] and said, “What if they will not believe me or take seriously what I say? For they may say, ‘The LORD has not appeared to you.’ ” And the LORD said to him, “What is that in your hand?” And he said, “A staff.” Then He said, “Throw it on the ground.” So Moses threw it on the ground, and it became a [living] serpent [like the royal symbol on the crown of Pharaoh]; and Moses ran from it. But the LORD said to Moses, “Reach out your hand and grasp it by the tail.” So he reached out his hand and caught it, and it became a staff in his hand— [“You shall do this,” said the LORD,] “so that the elders may believe that the LORD, the God of their fathers, the God of Abraham, the God of Isaac, and the God of Jacob, has [most certainly] appeared to you.” The LORD also said to him, “Put your hand into your robe [where it covers your chest].” So he put his hand into his robe, and when he took it out, his hand was leprous, as white as snow. Then God said, “Put your hand into your robe again.” So he put his hand back into his robe, and when he took it out, it was restored [and was] like the rest of his body. “If they will not believe you or pay attention to the evidence of the first sign, they may believe the evidence of the second sign. But if they will not believe these two signs or pay attention to what you say, you are to take some water from the Nile and pour it on the dry ground; and the water which you take out of the river will turn into blood on the dry ground.”