The phrase “the angel of the Lord” occurs 58 times in 19 Old Testament passages. Three of these passages are in Zechariah. The name appears to designate a unique being distinct from and possessing greater authority than other angels, one who identifies himself with deity and acts as if he were God.
We know the Lord Jesus was active on God’s behalf during the OT period. When we add to that John’s claim that no one has ever seen God, and that God has been (and continues to be) made known only through his Son, the Word, the logical conclusion is that the angel of the Lord was a visual manifestation of the preincarnate Christ.
More on that shortly.