XIII. Melchizedek

A man appears in Genesis 14 for three verses, blesses Abraham, accepts a tenth of the spoils, and disappears. He has no recorded genealogy. He's not from the line of Aaron (which won't exist for 400+ years). He is king of Salem (probably Jerusalem) and priest of God Most High (El Elyon). His name means "King of Righteousness." His title means "King of Peace."

Until Psalm 110:4 — a Davidic psalm:

David, writing prophetically about his "Lord" (Ps 110:1 — the verse Jesus uses to stump the Pharisees in Matt 22:41–46), says this Lord will have a priesthood — but not from Aaron's line. David himself was from Judah, not Levi; kings were not priests. Instead: after the order of Melchizedek. A different priestly line. An older one.

Then silence for another 1,000 years. Until Hebrews 5–7, where the author builds an entire theology of Christ's priesthood on this obscure figure.