4 And the Lord said to Moses, Put out your hand and take it by the tail: (and he put out his hand and took a grip of it and it became a rod in his hand:) 5 So that they may be certain that the Lord, the God of their fathers, the God of Abraham, of Isaac, and of Jacob, has been seen by you. 6 Then the Lord said to him again, Put your hand inside your clothing. And he put his hand inside his robe: and when he took it out it was like the hand of a leper, as white as snow. 7 And he said, Put your hand inside your robe again. (And he put his hand into his robe again, and when he took it out he saw that it had become like his other flesh.) 8 And if they do not have faith in you or give ear to the voice of the first sign, they will have faith in the second sign. 9 And if they have no faith even in these two signs and will not give ear to your voice, then you are to take the water of the Nile and put it on the dry land: and the water you take out of the river will become blood on the dry land.
Matthew Henry's Commentary on Exodus 4:4-9
Commentary on Exodus 4:1-9
(Read Exodus 4:1-9)
Moses objects, that the people would not take his word, unless he showed them some sign. God gives him power to work miracles. But those who are now employed to deliver God's messages to men, need not the power to work miracles: their character and their doctrines are to be tried by that word of God to which they appeal. These miracles especially referred to the miracles of the Lord Jesus Christ. It belonged to Him only, to cast the power of the devil out of the soul, and to heal the soul of the leprosy of sin; and so it was for Him first to cast the devil out of the body, and to heal the leprosy of the body.