The hour of Jesus's death was drawing near. As the day of the Passover approached, Jesus decided that he would take one last opportunity to prepare his disciples for the catastrophe that awaited them. So he sent two of his disciples, Peter and John (Luke 22:8), ahead of him to make preparations for the Passover meal.
Whether jesus had previously arranged for the use of the upper room, we do not know. Certainly, it was quite unusual, in that day, for a man to be carrying a water jar upon his head. This was a task usually assigned to the women. It is quite possible that Jesus used this unusual procedure in directing Peter and John to the appointed place because he did not want the rest of the group to know of the location in advance. If Judas had known, he might have seized the opportunity to advise the chief priests of Jesus's whereabouts.
As the group reclined around the table in the upper room, Jesus ate his last meal with his beloved followers (Luke 22:15). In a real sense, it was the last Passover meal that any of his group would eat for, thereafter, the religious rite of most significance to them would no longer be the Passover of the Old Testament but the Memorial Supper of the new covenant.
It was probably towards the end of the Passover meal that Jesus announced the presence of a traitor in their midst. Apparently, the disciples had not suspected Judas Iscariot of disloyalty. At Jesus's words they began to look, not at one another, but each man into his own heart, saying, Surely not I? (Mark 14:19)
In response, Jesus declared that it was, indeed, one of them, and went on to say, The Son of Man will go just as it is written about him. But woe to the man who betrays the Son of Man! It would be better for him if he had not been born. (Mark 14:21) It was God's foreordained purpose that Jesus should be crucified, but the responsibility for his betrayal lay, not with God, but with the betrayer.
It was at this point that Jesus instituted the Memorial Supper. Jesus took bread, gave thanks and broke it, and gave it to his disciples, saying, Take it; this is my body. Then he took the cup, gave thanks and offered it to them,and they all drank from it. This is my blood of the covenant, which is poured out for many. (Mark 14:21-24)
It is quite significant that the eating of the Passover meal was immediately followed by the observance of the Memorial Supper. Jesus sees himself in this meeting as bringing to a close the old sacrificial system and as founding a new covenant between God and his people. The old sacrificial system, represented in the sacrifice and the Feast of the Passover, he sees fulfilled in the new covenant. In this transition from an old to a new dispensation, Jesus interprets his death as the effectuating cause, the central factor. He pictures his blood as the seal of this new covenant. As an everlasting memorial of this new covenant, he founds the new Supper of the bread and the wine (fruit of the vine), the symbols of the giving of his body and his blood to seal the covenant.
As we partake of the Lord's Supper, each of us is to be consciously aware of the fact that he died for me.