15. for this cause--Because of the all-cleansing power of His blood, this fits Him to be Mediator (Heb 8:6, ensuring to both parties, God and us, the ratification) of the new covenant, which secures both forgiveness for the sins not covered by the former imperfect covenant or testament, and also an eternal inheritance to the called.
      by means of death--rather, as Greek, "death having taken place." At the moment that His death took place, the necessary effect is, "the called receive the (fulfilment of the) promise" (so Lu 24:49 uses "promise"; Heb 6:15; Ac 1:4); that moment divides the Old from the New Testament. The "called" are the elect "heirs," "partakers of the heavenly calling" (Heb 3:1).
      redemption of . . . transgressions . . . under . . . first testament--the transgressions of all men from Adam to Christ, first against the primitive revelation, then against the revelations to the patriarchs, then against the law given to Israel, the representative people of the world. The "first testament" thus includes the whole period from Adam to Christ, and not merely that of the covenant with Israel, which was a concentrated representation of the covenant made with (or the first testament given to) mankind by sacrifice, down from the fall to redemption. Before the inheritance by the New Testament (for here the idea of the "INHERITANCE," following as the result of Christ's "death," being introduced, requires the Greek to be translated "testament," as it was before covenant) could come in, there must be redemption of (that is, deliverance from the penalties incurred by) the transgressions committed under the first testament, for the propitiatory sacrifices under the first testament reached only as far as removing outward ceremonial defilement. But in order to obtain the inheritance which is a reality, there must be a real propitiation, since God could not enter into covenant relation with us so long as past sins were unexpiated; Ro 3:24, 25, "a propitiation . . . His righteousness for the remission of sins that are past."
      might--Greek, "may receive," which previously they could not (Heb 11:39, 40).
      the promise--to Abraham.

JFB.