Adam Clarke's Bible Commentary Verse 5. That they may believe] This is an example of what is called an imperfect or unfinished speech, several of which occur in the sacred writings. It may be thus supplied: Do this before them, that they may believe that the Lord-hath appeared unto thee.
Matthew Henry Commentary
Verses 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 thos 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 miracle especially referred to the miracles of the Lord Jesus Christ. I 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 firs to cast the devil out of the body, and to heal the leprosy of the body.
Original Hebrew למען4616 יאמינו539 כי3588 נראה7200 אליך413 יהוה3068 אלהי430 אבתם1 אלהי430 אברהם85 אלהי430 יצחק3327 ואלהי430 יעקב׃3290