This study proposes that Hebrews in its primary socio-historical context was an interpretation of Paul's epistle to the Romans, designed to clarify aspects of that epistle for a readership devoted to its content. As others already have suggested, internal and external evidence bespeak a relationship between the two texts. According to this study, the grist for Hebrews‚ mill is Paul's claim, in Rom 3:21ff., that Christ's death as a hilasterion not only offers atonement apart from the Law for those who believe, but also enables such believers, most of whom are gentiles, to become the genuine descendants of Abraham and consequently to inherit the promises stored up for those of such status. The latter is a theme to which Paul will famously return in Romans 9-11. The link between faith in Christ's sacrifice and reconfigured Abrahamic descent and inheritance is hardly transparent, however. Hebrews, I will argue, clarifies and enhances this link through its identification of Christ as a self-sacrificing High Priest after the order of Melchizedek. On the one hand, this identification underscores the novelty of Christ's sacrifice and its ability to mediate a new covenant and a new (and superior) mode of atonement; on the other hand, it provides the prototype for the reconfiguration of descent experienced by believers, for just as Christ reckons his priestly status through an alternative to the old covenant and the fleshly descent of the Levites, so the people he serves in the new covenant reckons its descent from Abraham, and its pursuant claim to the promises, in non-fleshly terms. Hebrews, then, advances Paul's assertion that the genuine „descendants of Abraham" (Heb 2:16) and the „heirs of the promise" (Heb 6.17) are those who have hope in Christ's unique and unprecedented sacrifice, not those whose descent is reckoned through flesh and the Law.