So; in the Catholic understanding of this subject; the “Eucharist” “re-presents” the Passover? Or, are you saying that by the Eucharist, grace is conferred upon the suppliant or partaker thereof?
The Passover, for Israel, re-presented the Exodus. That’s why it was eaten with loins girt, staff in hand, throughout generations. And the Passover lamb had to be
eaten, not just killed and cooked. You had to partake of it. For a Jew to celebrate the Passover, they celebrate not their
ancestors’ liberation from slavery, but their own.
The Eucharist, for (Catholic and Orthodox) Christians, re-presents the sacrifice of Jesus Christ on the cross in an unbloody manner, just as Christ pre-presented his sacrifice for the Apostles in an unbloody manner. The Mass is not so much a recreation of the Last Supper as it is
our experience at the foot of the cross. And, true to form, we eat of the Paschal Lamb, not in a cannibalistic way of course, but in a true and sacramental way.
There are many other connections which, although not written in Scripture, begin to reveal themselves from study of the Passover as celebrated at the time of Christ. The evangelists don’t describe in detail the Passover meal Jesus shared with his Apostles, but knowing what goes into such a meal gives a context to what Jesus did. It seems most likely that the bread he blessed and broke was the
afikomen (“that/he which is to come”), a piece of matzoh bread which is broken and distributed to each guest; the meal cannot resume until this has been done. After that comes the third cup of wine (of four). Jesus stopped the meal before its end: he ended the meal after this third cup, the “cup of blessing” as Paul calls it, also known as the “cup of redemption” or “salvation” – they didn’t drink the fourth cup! They went to Gethsemane singing hymns: the Hallel psalms (113-118), which are sung after the third cup. While in the garden, the “suspended” Passover was kept up: Jesus prayed that the “cup” might pass him by. Which cup? Well, there was yet the fourth cup to drink (the “cup of restoration”, which would bring
his Passover to its close), but Jesus is probably also referring to the “cup of wrath” (Isaiah 51:17). Jesus ended his Passover – “it is finished!” – on the cross in drinking the “wine” of sour vinegar offered to him, as John describes.
Another interesting point is found in Luke 24:13-32: Jesus opened up the Scriptures to his disciples on the road to Emmaus (cf. 24:27,32), but it was not until the breaking of the bread that they recognized the man they were with was Jesus. Put in another way, it was not by Scripture alone that they recognized Jesus in their midst, but by the Eucharist (after the Word).