Actually, the question about whether Passover occurred on the Thusday or the Friday is entirely a legitimate issue, but one which is dealt with in the bible, and incorporated into the Catholic/catholic tradition.
Jesus’ plan is to celebrate Passover with his disciples as a sign to Christians, yet be sacrificed himself later as a Passover sacrifice as a sign to the world. Praise the wondrous workings of God that this apparent contradiction is possible!
It is the passover which Jesus celebrates on THURSDAY evening. The day of unleavened bread was during the day on THURSDAY. Jesus himself is the paschal lamb offered on this feast. He means it when he says, “This is my body... This is my blood,” for it was on this day, THURSDAY, when he, the lamb of God, was consumed by the first Christians. That this is the passover is absolutely attested to:
“So they prepared the Passover. 14 When the hour came, Jesus and his apostles reclined at the table. 15 And he said to them, “I have eagerly desired to eat this Passover with you before I suffer. 16 For I tell you, I will not eat it again until it finds fulfillment in the kingdom of God.” — Luke 22:13b-16
Matthew is even plainer:
‘18 He replied, “Go into the city to a certain man and tell him, ‘The Teacher says: My appointed time is near. I am going to celebrate the Passover with my disciples at your house.’” 19 So the disciples did as Jesus had directed them and prepared the Passover. 20 When evening came, Jesus was reclining at the table with the Twelve. 21 And while they were eating, he said, “Truly I tell you, one of you will betray me.”’ — Matthew 27:18-21.
But how strange is this? The NEXT DAY after the passover meal, the Jews are preparing for the Passover ... again??? For after Jesus is flogged, John tells us “It was the day of Preparation of the Passover; it was about noon.” (John 19:13) Lest anyone have any doubt that the Passover was being celebrated on a Saturday, “Now it was the day of Preparation, and the next day was to be a special Sabbath.” (John 19:31).
Could Matthew and Luke depict a meal other than the Passover? No, it is celebrated when evening comes, after the Day of Preparation. How is it that John describes the events of the next day, and yet still insists that it is the Day of Preparation for the Passover? Because the Jews had conflicting ways of counting the Passover. The Essenes counted in one manner; the Sanhedrin in another. To this day, the Christian calculation of passover is inconsistent with the Jews.
The gospel is quite plain that Jesus is slain on the Day of Preparation for the Sabbath. That’s a Friday, folks.
Thus, God pulls off what seems to us to be a logical impossibility: Jesus celebrates the Passover meal with his disciples; yet also is himself the Paschal lamb.
In Matthew it is stated that the priest went to Pilot the day after the Preparation Day to demand that guards be placed at the tomb. Would the priest go to see a gentile on the Sabbath, and thus be unclean? Just a question.
Just so. The connection with the Passover involves typology, where a prophetic event in the Bible foreshadows another event, which “fulfills” it.
Thus, the account of Abraham’s sacrifice of Isaac involves a sheep caught in the bushes, which God accepts as a sacrifice in place of Abraham’s first-born son. That foreshadows the Passover, when the passover lambs are offered as a sacrifice in place of the first born sons. And that, in turn, foreshadows the Last Supper and the Crucifixion, in which Jesus is the Lamb of God, as he appears in the Book of Revelation.
One might also note that, in this way, the New Covenant does not cancel out and replace God’s old Covenant with the Jews (which God says is “forever” and Paul repeats that phrase in one of his epistles), but rather it fulfills it. The Jews are lovingly invited into the New Covenant, but they are not forced into it. Apparently it will take until the Last Days before they all come over.
Yes, He had the Passover supper the evening before Passover began, because He knew that He would not be alive for the actual Passover.