The Pope’s presentation in “Jesus of Nazareth” II is confusing pp. (106-115). However, he ends with one of his main themes, viz. that Jesus Christ is the Revelation and meaning of all Scripture. In this context, Christ did not eat the Passover meal with a slain lamb because they were to be slain the next day, and He was to be crucified at the same time as their slaying (Raymond Brown). The festal Paschal meal was to be eaten on Thursday evening that year because the feast was celebrated on Friday ("St. John 18, 28: "they themselves did not enter the praetorium, that they might not be defiled, but might eat the passover"). This was to mean that Christ was crucified on Thursday and that the Last Supper – Christ’s new Paschal Meal – was celebrated on Wednesday: “This farewell meal was not the old Passover, but the new one, which Jesus accomplished in this context. Even though the meal that Jesus shared with the Twelve was not a Passover meal according to the ritual prescriptions of Judaism, nevertheless, in retrospect, the inner connection of the whole event with Jesus’ death and Resurrection stood out clearly. It was Jesus’ Passover. And in this sense he both did and did not celebrate the Passover: the old rituals could not be carried out – when their time came, Jesus had already died. But he had given himself, and thus he had truly celebrated the Passover with them. The old was not abolished; it was simply brought to its full meaning.”
Scott Hahn follows Annie Jaubert’s thesis:
I find the supposed conflict between the synoptics and John is resolved to my satisfaction by Annie Jaubert, The Date of the Last Supper (Staten Island: Alba House, 1965). She argues two calendars were operative in Christ’s time and accepts the ancient Syriac testimony of a "Holy Tuesday" institution of the Eucharist. Granted, there are difficulties in that, but her work helps harmonize the five trials of Jesus (Annas, Caiaphas, Pilate, Herod, and Pilate), which fit much easier into a Tuesday to-Friday time frame than in a Thursday-midnight-to-morning frame. She also published an article arguing that even John’s account of the upper room shares a paschal background, "The Calendar of Qumran and the Passion Narrative in John," in J. Charlesworth, ed., John and Qumran (London: Geoffrey Chapman, 1972), 62-75. I have read criticisms of Jaubert’s thesis, but I don’t feel much force behind them; for a popular summary of the alleged problems, see Raymond Brown, "The Date of the Last Supper," in The Bible Today Reader (Collegeville: Liturgical Press, 1973), 322-28.] John depends on irony in depicting the Kingdom glory of Jesus in connection with the suffering of the cross: "And Jesus answered them, ]The hour has come for the Son of man to be glorified. . . . Now is the judgment of this world, now shall the ruler of this world be cast out; and I, when I am lifted up from the earth, will draw all men to myself.' He said this to show by what death he was to die" (John 12:23, 31-33). With profound spiritual insight, John links Jesus’ "hour of glory" with the supreme manifestation of his love upon the cross (John 3:14, 7:37-39, 8:28, 13:31). Following this to the end of the fourth Gospel, I began to notice several places where John deliberately weaves together various strands of Kingdom and Passover imagery in depicting Jesus’ trial and passion. The result was to draw a little nearer to what Jesus meant when he said, "It is finished" (John 19:30). First, Jesus’ claim to kingship in John comes precisely at the moment when he appears weakest and most vulnerable--when he is standing accused before Pilate (18:33-37). Pilate’s cynical response is to dress him in a purple robe with a crown of thorns and to present him to his own unbelieving people: "Now it was the day of preparation of the Passover; it was about the sixth hour. He said to the Jews, 'Behold your King!' They cried out, 'Away with him, away with him, crucify him!'" (19:14). John realized that the sixth hour was when the priests were prescribed to begin slaughtering lambs for the Passover. Second, only John mentions that Jesus was stripped of a seamless linen tunic (19:23-24). The same word for "garment" (chiton) is used in the Old Testament for the official tunic worn by the High Priest in sacrifice (Ex. 28:4; Lev.16:4). This is meant to remind faithful readers that Jesus, their glorious King and Passover lamb, is also the High Priest of the New Covenant (19:23-24). Third, the identification of Jesus with the Passover lamb is reinforced by John’s noting Jesus’ bones remained unbroken, as prescribed by the law for the Passover lamb (Ex. 12:46): "that the Scripture might be fulfilled, 'Not a bone of him shall be broken'" (19:33, 36). This brings to fulfillment the words used in John’s introduction of Jesus at the start of his Gospel: "Behold the lamb of God who takes away the sin of the world" (1:29). GRADUALLY these Passover and Kingdom themes from John’s Gospel began to converge in my mind as I reapproached the question of Jesus’ meaning in saying, "It is finished" (John 19:30). For one thing, I noticed that my King, Priest, and paschal victim, in his "hour of glory" while suffering on the cross, made a profound gesture: "After this Jesus, knowing that all was now finished, said (to fulfill the Scripture), 'I thirst.'" Jesus was thirsty long before this closing moment of his life. His words, therefore, must reflect more than a desire for a last drink of fluid. He seems to have been in full possession of himself as he realized that "all was now finished." Whatever it is that "was now finished" seems to be directly connected to his utterance, which he spoke "to fulfill the Scripture." More things fall into place upon reading what followed his expression of thirst: "A bowl of sour wine stood there; so they put a sponge full of the vinegar on hyssop and held it to his mouth" (19:29). Only John noticed that hyssop was used, the branch prescribed in the Passover law for sprinkling the blood of the lamb (Ex.12:22). This verse reveals something significant. Jesus had left unfinished the Passover liturgy in the upper room by not drinking the fourth cup. He stated his intention not to drink wine again until he came into the glory of his Kingdom. As we have seen, he refused some on one occasion, right before being nailed to the cross (Mark 15:23). Then, at the very end, Jesus was offered "sour wine" (John 19:30; Matt.27:48; Mark 15:36; Luke 23:36). But only John tells us how he responded: "When Jesus had received the sour wine, he said, 'It is finished'; and he bowed his head and gave up his spirit" (19:30). AT LAST I had an answer to my question. It was the Passover that was now finished. More precisely, it was Jesus’ transformation of the Passover sacrifice of the Old Covenant into the Eucharistic sacrifice of the New Covenant. I learned Scripture teaches that the Passover sacrifice of the New Covenant began in the upper room with the institution of the Eucharist, not merely with Jesus being crucified on Calvary, as I was taught and had been teaching. In Jesus’ mind, his Eucharistic sacrifice as the Passover lamb of the New Covenant was not finished until Calvary. In sum, Calvary begins with the Eucharist and the Eucharist ends with Calvary. It is all of one piece.