But I would add that he also a King. This is important because is it is the best argument against Melchizedek being an angel, theophany or even Jesus preincarnate which I always felt was the most likely answer.
I am reading a book as I am tracking down the Trinity in the OT. From the book the author gives 8 basic facts concerning God’s appearances in the OT:
(1) theophanies are actual appearances and not imaginary.
(2) they are initiated by God.
(3) they are revelatory, meaning that God’s primary purpose was to reveal, at least in a partial manner, something about Himself or His will, to the recipient.
(4) they were for individuals.
(5) they were intermittent in appearance.
(6) they were also temporary.
(7) they were audible and visible.
(8) they did vary in form.
Fruchtenbaum, D. A. G. (2010). Foreword. In Discovering the Mystery of the Unity of God: A Theological Study on the Plurality and Tri-unity of God in the Hebrew Scriptures (p. 258). San Antonio, TX: Ariel Ministries.
Items 5&6 are the major points that I believe can be applied as proof that Melchizedek was a human. He had a name, he was the King of Salem (Jerusalem) and because of this he was responsible to his subjects. He was a priest of a different order and worshiped the Most High God.
I think it is noteworthy to remember that in the OT Melchizedek never claimed a divine status nor was it asigned and the NT in Hebrews (a book that speaks of the contrast of good and superior, Moses was good Jesus is superior). Here are two excerpts that will better explain this position, the first from F.F. Bruce.
The words which follow present an outstanding example of the argument from silence in a typological setting. When Melchizedek is described as being “without father, without mother, without genealogy, having neither beginning of days nor end of life,” it is not suggested that he was a biological anomaly, or an angel in human guise. Historically Melchizedek appears to have belonged to a dynasty of priest-kings in which he had both predecessors and successors. If this point had been put to our author, he would have agreed at once, no doubt; but this consideration was foreign to his purpose. The important consideration was the account given of Melchizedek in holy writ; to him the silences of Scripture were as much due to divine inspiration as were its statements. In the only record which Scripture provides of Melchizedek—Gen 14:18–20—nothing is said of his parentage, nothing is said of his ancestry or progeny, nothing is said of his birth, nothing is said of his death. He appears as a living man, king of Salem and priest of God Most High; and as such he disappears. In all this—in the silences as well as in the statements—he is a fitting type of Christ; in fact, the record by the things it says of him and by the things it does not say has assimilated him to the Son of God. It is the eternal being of the Son of God that is here in view; not His human life. Our author has no docetic view of Christ; he knows that “our Lord hath sprung out of Judah” [Hebrews 7:14]. But in His eternal being the Son of God has really, as Melchizedek has typically, “neither beginning of days nor end of life;” and more especially now, exalted at the right hand of God, He “abideth a priest continually.” Melchizedek remains a priest continually for the duration of his appearance in the biblical narrative; but in the antitype Christ remains a priest continually without qualification. And it is not the type that determines the antitype, but the antitype that determines the type; Jesus is not portrayed after the pattern of Melchizedek, but Melchizedek is “made like unto the Son of God.”
Fruchtenbaum, D. A. G. (2010). Foreword. In Discovering the Mystery of the Unity of God: A Theological Study on the Plurality and Tri-unity of God in the Hebrew Scriptures (p. 261). San Antonio, TX: Ariel Ministries.
And this one from Arnold Fruchtenbaum’s book on Hebrews:
(1) In this text he does not use an adjective that would describe Melchizedek in his being and essence to be like the Son of God; instead, he uses a participle, meaning that Jesus was similar to Melchizedek only in the likeness of the biblical statement. The word used for being made is found only here in the Greek New Testament. (2) He states that Melchizedek was like the Son of God; it does not say that he “was” the Son of God in the Old Testament. (3) The second passage where he is mentioned, Psalm 110:4, distinguishes Melchizedek from the Messiah. (4) According to Hebrews 5:1, one of the pre-requisites for priesthood was that the priest had to be human. Jesus did not become a man until the incarnation when He was conceived by the Holy Spirit in the womb of Mary (Miriam). Before that time, Jesus appeared in the form of a man, but He was not an actual man. (5) Another reason why Melchizedek could not have been a theophany is that, in the Old Testament, theophanies appeared and disappeared; they held no long-term office. The Melchizedek of Genesis 14 was a king of the city-state of Jerusalem, which required a position and a permanent residency. Theophanies never had a position; they were always short and temporary manifestations.
Fruchtenbaum, D. A. G. (2010). Foreword. In Discovering the Mystery of the Unity of God: A Theological Study on the Plurality and Tri-unity of God in the Hebrew Scriptures (pp. 261–262). San Antonio, TX: Ariel Ministries.
I hope this doesn’t muddy the water.