In Genesis 14: 18-20 there is a person who is mentioned. His name is Melchizedek. He was both the king of Salem and a priest (translated king of peace (Heb 7:2)). I find this interesting because right in the middle of the story of Abram (Abraham) this man is mentioned and everything is focusing on the Abrahamic covenant. The interesting part is that every source I have refers to him as a "type of Christ" and nothing to do with the Abrahamic covenant.
Then Melchizedek king of Salem brought out bread and wine; he was the priest of God Most High. And he blessed him and said: "Blessed be Abram of God Most High, Possessor of heaven and earth; And blessed be God Most High, Who has delivered your enemies into your hand." And he gave him a tithe of all.
The next time he is mentioned is Psalm 110:4
The Lord has sworn And will not relent, "Your are a priest forever According to the order of Melchizedek."
Later in the book Hebrews the writer refers to Psalm 110:4 four times (5:6; 6:20; 7:17; and 7:21). However, chapter seven spends more time using Melchizedek as an example to Jesus Christ's priesthood and expounds on Christ's superiority.
without father, without mother, without genealogy, having neither beginning of days nor end of life, but made like the Son of God, remains a priest continually.
There are few that take it literally or claim there is a better translation that Melchizedek had no parents and lived forever. It is simply a comparison and I emphasize "like" in Hebrews 7:3.
So what is the point of this? In my opinion I think he is a prototype of Christ and used to illustrate to the Jews. For instance, the author started talking about Melchizedek and Christ's priesthood, but stopped because he did not think they would understand (Hebrews 5:1-11).
I am still looking into this, but I implore you to as well if you have not already.
What are your thought?