Hebrews 9:15

“And for this cause he is the Mediator of the New Testament, etc..] (See Gill on “<580722>Hebrews 7:22”), (see Gill on “<580806>Hebrews 8:6”), (see Gill on “<580808>Hebrews 8:8”). This may refer both to what goes before, and what follows after; for Christ, that he might offer himself to God, and by his blood purge the consciences of his people from dead works, that so they might serve the living God, became the Mediator of the New Testament, or covenant; and also he took upon him this character and office, that by means of death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance; Christ became…”

“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 Luk 24:49 uses "promise"; Heb 6:15; Act 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).…”

“And for this cause - With this view; that is, to make an effectual atonement for sin, and to provide a way by which the troubled conscience may have peace. He is the Mediator - see notes on Galatians 3:19-20. He is the Mediator between God and man in respect to that new covenant which he has made, or that new dispensation by which people are to be saved. He stands between God and man - the parties at variance - and undertakes the work of mediation and reconciliation. Of the New Testament - Not “testament” - for a “testament,” or “will,” needs no mediator; but of the “new covenant,” or the new “arrangement” or “disposition” of things under which he proposes to pardon and save the guilty; see…”

“And for this end he is the Mediator of a new covenant, that they who are called - To the engagements and benefits thereof. Might receive the eternal inheritance promised to Abraham: not by means of legal sacrifices, but of his meritorious death. For the redemption of the transgressions that were under the first covenant - That is, for the redemption of transgressors from the guilt and punishment of those sins which were committed in the time of the old covenant. The article of his death properly divides the old covenant from the new. Hebrews 9:16”

“9:15 the one who mediates: This term refers to an arbiter in a difficult legal dispute or political disagreement. In the old covenant, Moses and the angels were understood as mediators between God and the people (Gal 3:19-20). In the new covenant, Christ mediates the relationship between God and people by his sacrificial death (Heb 8:6; 12:24; Rom 6:23; 1 Tim 2:5; 1 Pet 3:18) and ongoing intercession (Heb 7:25).”

“the mediator: Heb 7:22, Heb 8:6, Heb 12:24; Ti1 2:5 the new: Heb 8:8; Co2 3:6 means: Heb 9:16, Heb 9:28, Heb 2:14, Heb 13:20; Isa 53:10-12; Dan 9:26 for: Heb 9:12, Heb 11:40; Rom 3:24-26, Rom 5:6, Rom 5:8, Rom 5:10; Eph 1:7; Pe1 3:18; Rev 5:9, Rev 14:3, Rev 14:4 the first: Heb 9:1, Heb 8:7, Heb 8:13 they which: Heb 3:1; Rom 8:28, Rom 8:30, Rom 9:24; Th2 2:14 promise: Heb 6:13, Heb 11:13, Heb 11:39, Heb 11:40; Jam 1:12; Jo1 2:25 eternal: Psa 37:18; Mat 19:29, Mat 25:34, Mat 25:36; Mar 10:17; Luk 18:18; Joh 10:28; Rom 6:23; Ti2 2:10; Tit 1:2, Tit 3:7; Pe1 1:3, Pe1 1:4, Pe1 5:10 Hebrews 9:16”