Hebrews 7 picks up themes that are familiar already to readers of the book. The writer defends the superiority of Christ’s priesthood to the Levitical priesthood of the Old Testament on the basis of his connection to Melchizedek. A key part of this strategy is to declare that Levi “paid tithes to Melchizedek, being still in the loins of his ancestor” (Abraham). How are we to understand this idea? This episode tackles this difficult issue, as well as the tradition that Melchizedek was Noah’s son Shem.
McNamara, “Melchizedek: Gen 14:17-20 in the Targums, in Rabbinic and Early Christian Literature,” Biblica 81 (2000)