Some of the details we are familiar with are not found in this version. 1 Corinthians 11:23-26 is the earliest written version of the Lord’s Supper (or Communion, or Eucharist), Luke 22:19-23 has similar words focusing on the bread and wine. What is important about 1 Corinthians 11:23-26 is that Paul uses the words “on the night he was betrayed” and all three synoptic gospels include the prediction of betrayal as part of the meal.
There were many other parts of a Passover meal which Jesus does not reinterpret as anticipating his death. Jesus does not comment on eating lamb or the bitter herbs, etc. All of this is completely familiar to a Jewish reader, in the same way an American does not need to explain to Americans the food on the table at a thanksgiving meal (everyone knows: turkey, mashed potatoes and stuffing, cranberry sauce, that weird sweet potato dish with the marshmallows, etc.) Matthew only includes the elements of the meal Jesus uses to explain the kind of death he was about to die, the two elements which become part of Christian worship practice in the earliest Christian communities.
The bread is his body (26:26). Remember this is unleavened bread, Jesus broke (κλάω) the bread. The verb s only used for breaking bread in the New Testament (Matt 14:19, 15:26, the two feeding miracles and this passage). As in English, “break bread” can refer to eating a meal (Acts 20:7, 11, although this arguably could be a communion). In classical Greek the verb is used for breaking branches (‘snap” for example, BrillDAG).
In Deuteronomy 16:3, the unleavened bread was called “bread of affliction.” If the bread is unleavened, then breaking the bread is a visual analogy to what is about to happen to Jesus’s body. Although his bones are not broken, his body will be beaten and abused. Nolland (and others) suggest sharing the bread occurred during a question an answer part of the Passover meal based on Exodus 12:26-27. By sharing the bread, Jewish families were demonstrating that they were part of the community that was redeemed from slavery in Egypt by the blood of the lamb (Matthew, 1075). They are looking back to the salvation event of the Old Testament, when God imitated a covenant with his people.
The cup is the blood of the covenant (26:27-28). During the Passover meal, there were four cups of wine associated with stages in the meal. Most scholars think this is the third cup, the cup of blessing. It came after the meal and the father pronounced a blessing on the cup (as Jesus does in verse 27).
Sharing a cup of wine is unusual for a Passover meal. Each person has their own cup to drink from when the blessing is offered. Think of the way protestants do communion. Everyone gets their own mini-cup rather than sharing a single cup of wine. This may be logistical, sharing a single cup among 500 people is not practical. In this case, the sharing may indicate the covenant Jesus is inaugurate is for all the disciples equally. We often make the point that sharing the bread and the cup is a sign of Christian unity, based on 1 Corinthians 11.
Matthew does not include the word “new” (1 Cor 11:25; Luke 22:20). In the King James Version, the words “new testament” appear, but the word “new” is likely not part of Matthew’s original text. It was added by later scribes who knew the communion liturgy from 1 Corinthians 11:25 or Luke 22:20. The word “testament” is a translation of the Greek word διαθήκη, now commonly translated as “covenant” because “testament” does not mean the same thing as covenant in contemporary English.
Matthew describes the blood as “poured out for many” and adds the phrase “for the forgiveness of sins” (Mark 14:24). Blood “poured out” (ἐκχέω) can refer to a violent death (Gen 9:6, referring to murder; the blood of the martyrs is “poured out” Matt 23:35; Acts 22:20, Stephen), so “poured out” may evoke Jesus’s physical death on the cross. But the word is used in the Septuagint in the context of sacrifice (Lev 4:7, for example). The word is commonly associated with drink offerings, pouring out a little bit of wine on an altar (Sirach 50:15, the high priest Simon son of Onias poured out the “blood of the grape” on the altar and made a pleasing odor to the Most High).
In LXX Exodus 24:6 Moses sprinkled (imperfect of ἐκχέω) blood on the altar when he read the book of the Covenant to the people. This is a very important Old Testament text for the last supper since God is inaugurating the original (old) covenant with blood, and seventy elders go up the mountain, see God’s glory and “ate and drank” (24:11). A covenant is usually established with a sacrifice and a shared meal (eating and drinking, almost always wine). Both Mark and Luke understand Jesus’s death as providing forgiveness of sins (Mark 1:4; Luke 1:77), but Matthew makes the connection between the sacrifice that Jesus is about to make and the forgiveness of sins.
Finally, Jesus predicts he will not drink the fruit of the vine again until he drinks new wine with the disciples in his Father’s kingdom (26:29). The point here is that the breaking of the body and the shedding of blood is in the very near future. Jesus is about to pour out his blood to inaugurate the new covenant.
But the idea of drinking wine in the kingdom of God evokes the eschatological banquet (Isa 25:6-8). The parable of the Wedding Banquet (Matt 25:1-13) describes the soon-coming kingdom of God as like a wedding banquet as doe the parable of the Ten Virgins (Matt 25:1-12).
The other way the Old Testament described the banquet at the beginning of the kingdom is a victory banquet, Psalm 23:4-5, the Lord makes a victory banquet in the presence of the anointed one’s enemies. Revelation 19 calls the utter devastation of the enemies of God the “marriage supper of the lamb” (and then calls on the birds to come consume the corpses).
They sing a final hymn and return to the Mount of Olives for the night. What was that last hymn? Likely one of the Hallel psalms (113-118). On the way, Jesus predicts Peter too will betray Jesus.