CIC 1544 Everything that the priesthood of the Old Covenant prefigured finds its fulfillment in Christ Jesus, the “one mediator between God and men.”1 The Christian tradition considers Melchizedek, “priest of God Most High,” as a prefiguration of the priesthood of Christ, the unique “high priest after the order of Melchizedek”;2 “holy, blameless, unstained,”3 “by a single offering he has perfected for all time those who are sanctified,”4 that is, by the unique sacrifice of the cross.

1 2 Tim 2:5.
2 Heb 5:10; cf. 6:20; Gen 14:18.
3 Heb 7:26.
4 Heb 10:14.