"The Last Supper is what transforms Jesus' execution into a sacrifice."
So Scott Hahn frequently tells audiences. He is right of course. As he frequently observes, no one standing at the foot of the cross would have described what was going on as a sacrificial offering. They would have described it as an execution.
What reveals the true meaning of Jesus' death? The Last Supper.
In light of that, here I want to revisit a topic I've looked at before, namely, the imagery of "atonement" at the Last Supper. As Jesus makes clear--in multiple ways, in fact!--his death is what accomplishes the "forgiveness of sins".
His Blood is "Poured Out"
Jesus' language of his blood being "poured out"--something found in all three Synoptic accounts of the Last Supper--evokes the Levitical law code. Not only does it call to mind the language of Leviticus 17, but also the fact that the blood of the sacrificial animals brought for atonement had to be "poured out" (cf. Lev 4:7, 18, 25, 30, 34).
Notably, the ritual of pouring out blood is also linked with the Day of Atonement in the Dead Sea Scrolls (cf. 11Q19 15:3; 23:13). These texts provide strong support for the antiquity of the traditions found in the Mishna which also link the pouring out of blood to the Yom Kippur liturgy (cf. m. Yoma 5:4, 7; cf. also b. Yoma 56b).
In fact, strikingly, certain sources explain that the blood was poured from cups. This is especially apparent in the Talmud (cf. b. Yoma 57b), though this is a much later source.
However, there is a particularly striking parallel between Jesus’ Eucharistic words and Sirach 50:15, which explains that on the Day of Atonement the duties of the high priest apparently involved “pouring out” (ἐξέχεεν) the “blood of the grape” (αἵματος σταφυλῆς) from a “cup” (σπονδείου) (cf. Sir 50:15).
That Jesus has spoken of his “blood” being “poured out” in connection with the wine in the “cup” is strikingly evocative of this text.
Jesus as the Suffering Servant
In Isaiah 53 we read about the Suffering Servant who “poured out his soul to death. . . he bore the sin of many” (Isa 53:12). The Suffering Servant is clearly linked to atonement imagery. He is explicitly described as a “sin-offering,” who, like the scapegoat of Yom Kippur, is said to “bear iniquities" and "he bore the sin of many" (Isa 53:10, 12).
Of course, it is widely accepted that Jesus' saying about his blood being "poured out for many" in Matthew and Mark (cf. Matt 26:27//Mark 14:24) is drawing on this prophecy.
The Account of the Last Supper in 1 Corinthians
In the account of the Last Supper in 1 Corinthians 11, Paul does not mention Jesus’ blood being “poured out.” But this does not mean that he does not see it as having atoning value!
First, it is possible that the very image of Jesus' "blood" would have evoked such imagery for Paul. Expiation is typically associated with Jesus' blood throughout the New Testament books, including in other Pauline letters (cf. Rom 3:25; 5:9; Eph 1:7; 2:13; Col 1:20; Heb 9:12, 14; 10:19, 29, 12:24; 13:12; 1 Pet 1:2, 19; 1 John 1:7; 5:6, 8; Rev 1:5; 5:9; 7:14; 12:11).
Confirmation that Paul has this in mind may be seen in the following.
