A.T. Robertson Commentary Matthew 26:28

"for this is my blood of the covenant, which is poured out for many unto remission of sins." — Matthew 26:28 (ASV)

The Covenant (της διαθηκης). The adjective καινης in Textus Receptus is not genuine. The covenant is an agreement or contract between two (δια, δυο, θηκε, from τιθημ). It is used also for will (Latin, testamentum) which becomes operative at death (Hebrews 9:15–17). Hence our New Testament. Either covenant or will makes sense here. Covenant is the idea in Heb 7:22; 8:8 and often. In the Hebrew to make a covenant was to cut up the sacrifice and so ratify the agreement (Genesis 15:9–18). Lightfoot argues that the word διαθηκε means covenant in the N.T. except in Heb 9:15-17. Jesus here uses the solemn words of Ex 24:8 "the blood of the covenant" at Sinai. "My blood of the covenant" is in contrast with that. This is the New Covenant of Jer 31; Hebrews 8.

Which is shed for many (το περ πολλων εκχυννομενον). A prophetic present passive participle. The act is symbolized by the ordinance. Cf. the purpose of Christ expressed in 20:28. There αντ and here περ.

Unto remission of sins (εις αφεσιν αμαρτιων). This clause is in Matthew alone but it is not to be restricted for that reason. It is the truth. This passage answers all the modern sentimentalism that finds in the teaching of Jesus only pious ethical remarks or eschatological dreamings. He had the definite conception of his death on the cross as the basis of forgiveness of sin. The purpose of the shedding of his blood of the New Covenant was precisely to remove (forgive) sins.