It was about the meal in which the lamb would be sacrificed.
Jesus and his disciples were celebrating the festival of the passover.
Jesus was the one who started the passover. The passover was a feast that Jesus wanted to have with his disciples (followers) before his death. That's why it is also called the Last Supper.
The theme is the last meal, the Passover meal, that Jesus shared with his disciples before being arrested.
Because he knew it was his last day on earth in his body with his disciples, and he gave it, his body and blood, for the disciples to remember him, and as a sign of the New Covenant in his blood and not the blood of a lamb, which is Passover.
Jesus fulfilled the Passover as was given to Moses as an example of His coming. For some Christians, Passover is a memorial of the sacrifice of Jesus Christ, "our Passover" which made possible the forgiveness of our sins.
The Last Supper was the Passover feast and appears in the Synoptic gospels, Matthew, Mark and Luke, because Passover occurred on the Thursday before the crucifixion. In John's Gospel, the Passover was on the Friday of the crucifixion, so there is no Last Supper recorded, instead Jesus washed the feet of the disciples.
In the synoptic gospels, Jesus and his disciples were celebrating the Jewish Passover on the night of his arrest; the Last Supper was their Seder meal. In John's Gospel, Jesus was arrested on the night before the Passover, thus instead of a detailed mention of the Last Supper, we have the account of Jesus washing their feet. The gospel says that Jesus was crucified on the day prior to the Passover, and makes greater use of Passover imagery than do the other gospels.
In the synoptic gospels, the Last Supper was on the day of the Jewish Passover feast, so we can say that Jesus and the disciples were partaking of the Passover feast.In John's Gospel, the crucifixion was on the day of preparation for the Passover, so John does not describe a Last Supper, saying just that on evening before, when their supper was ended, Jesus washed the feet of the apostles.
Jesus was free from the presence of his disciples as he had sent them on ahead of him to prepare for the Last Supper at Passover.
The last passover celebrated by Jesus and His Apostles (the Last Supper) was in a room called the "Cenacle" in a building that is traditionally believed to be on Mount Zion in Jerusalem.
The Last Supper of Jesus was a Jewish Passover meal, or Seder.
Jesus instituted and celebrated the first communion with His disciples at the passover feast we now refer to as the Last Supper.