How do we know Jesus is a priest in the order of Melchizedek?

The New Testament book of Hebrews explicitly refers to Jesus as a priest forever after the order of Melchizedek, citing Psalm 110:4. This priesthood is significant because it is not based on genealogy or law, but rather on God's eternal decree and oath. Hebrews 7 contrasts Jesus' priesthood with that of the Levitical priests, highlighting that Jesus, as a priest, has no beginning or end and brings perfect redemption. In this sense, Jesus fulfills and exceeds the role that Melchizedek played, acting as the ultimate high priest who is eternal and continually intercedes for the elect.