4 But the Lord said to Moses , "Stretch out your hand and grasp it by its tail "-so he stretched out his hand and caught it, and it became a staff in his hand - 5 "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 The Lord furthermore said to him, "Now put your hand into your bosom ." So he put his hand into his bosom , and when he took it out, behold , his hand was leprous like snow . 7 Then He said , "Put your hand into your bosom again ." So he put his hand into his bosom again , and when he took it out of his bosom , behold , it was restored like the rest of his flesh . 8 "If they will not believe you or heed the witness of the first sign , they may believe the witness of the last sign . 9 "But if they will not believe even these two signs or heed what you say , then you shall take some water from the Nile and pour it on the dry ground ; and the water which you take from the Nile will become blood on the dry ground ."
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.