Hebräer 8:13

he--God. made . . . old--"hath (at the time of speaking the prophecy) antiquated the first covenant." From the time of God's mention of a NEW covenant (since God's words are all realities) the first covenant might be regarded as ever dwindling away, until its complete abolition on the actual introduction of the Gospel. Both covenants cannot exist side by side. Mark how verbal inspiration is proved in Paul's argument turning wholly on the one word "NEW" (covenant), occurring but once in the Old Testament. that which decayeth--Greek, "that which is being antiquated," namely, at the time when Jeremiah spake. For in Paul's time, according to his view, the new had absolutely set aside the old covenant. The Greek for (Kaine) New (Testament) implies that it is of a different kind and supersedes the old: not merely recent (Greek, "nea"). Compare Hos 3:4-5. Next: Hebrews Chapter 9

In this chapter the apostle pursues his former subject, the priesthood of Christ. And, I. He sums up what he had already said (Heb 8:1, Heb 8:2). II. He sets before them the necessary parts of the priestly office (Heb 8:3-5). And, III. Largely illustrates the excellency of the priesthood of Christ, by considering the excellency of that new dispensation or covenant for which Christ is the Mediator (Heb 8:6 to the end).

8:13 The word new in “new” covenant emphasizes that, once God had enacted this covenant, the Sinai covenant was considered old or obsolete and was thus out of date. Its time of usefulness was over and its termination was imminent.