During the meal, that some term,”The Last Supper”, Rabbi Jesus broke bread with his closest friends and shared (most likely watered) wine. (See references at end.)
According to Prof. James Tabor–in his book, Paul and Jesus–Paul (Saul of Tarsus) had a vision of Jesus (1Co 12:1-4) explaining the metaphorical significance of this fellowship meal to Paul. From these statements, in the Christian New Testament letters of Paul, arose the doctrine of transubstantiation (bread=body, blood=wine).
My take on this meal–and Jesus’ and Paul’s statements about it–is, that when we share food and drink in the fellowship of love (Mt 18:12) we all become one body kept spiritually alive by the blood flowing through the body, this being a metaphor for Adonai’s spirit (the blood) of Jewish unity (the body). No more nor less. Later on theologians amplified this meal’s significance with supernatural aspects and it was solidified into doctrine by the Council of Nicea at the Roman Emperor Constantine’s behest.
As to whether or not it was a Passover Seder is continuosly debated, but I think not. Below is a corroborative statement by Rabbi Gershon Steinberg-Caudill:
“The REASON the Last Supper was NOT a Passover Seder is based on the traditions of the Jewish people AND the “other Gospels.” The Romans would not have crucified Jesus on Passover for fear of causing a riot, which were especially volatile during the time of the Freedom Festival of Passover. If the Last Supper had been a Passover Seder, the next day would also have been Passover (a Seven day Festival).”
But, I DO believe Jesus knew it was his LAST meal, because he had set it up beforehand to be handed over to the Romans (Joh 13:27); yet that is another tale.
Mt 26:26; Mk 14:22; Lu 22:19; Joh 6:53-56; 1Co 10:16-17, 11:24-29; Gal 1:16; Heb 2:14, 9:20