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.

2. the Lord said, … What is that in thine hand?—The question was put not to elicit information which God required, but to draw the particular attention of Moses.

A rod—probably the shepherd's crook—among the Arabs, a long staff, with a curved head, varying from three to six feet in length.