I’m taking an on-line course on catechesis and the following caught my attention (from Dr. Scott Hahn’s Book, A Father Who Keeps His Promises):
Jesus instituted the Eucharist during the course of a Passover meal. This memorial celebrated God’s deliverance of Israel from Egypt. At the first Passover, every firstborn son in Egypt perished except those in Israelite families where a lamb was slain and eaten as a sacrificial meal.
Then Moses led Israel out of Egypt to Sinai, where they became God’s family, the “chosen people,” through what is known as the Old Covenant.
The one time Jesus used the word “covenant” was at the Last Supper. There the firstborn Son and Lamb of God fulfilled the Old Covenant Passover in Himself, as a sacrifice for our sins. On that occasion Jesus announced the establishment of the New Covenant (see Mt. 26:27-28).
The cup of wine that Jesus changed into His blood was the “cup of blessing” (cf. 1 Cor. 10:16). This was the third cup of wine that was served during the Passover liturgy. There was still a fourth cup remaining, the “cup of consummation.”
Yet, instead of proceeding with the fourth cup, Jesus went out to the Mount of Olives (Mk. 14:26). This was a significant omission, and one that Jesus seemed to notice when He said in the preceding verse: “Truly, I say to you, I shall not drink again of the fruit of the vine until that day when I drink it new in the kingdom of God” (Mk. 14:25).
It seems that Jesus intended not to drink the cup that His disciples expected Him to drink.
In the Garden of Gethsemane, Jesus three times prayed that “this cup” would be taken away. Later, as Jesus was being led to His execution, He was offered wine and did not take it (Mk. 15:23).
Finally, we read: “After this Jesus, knowing that all was now finished, said (to fulfill the Scripture), ‘I thirst.’ A bowl full of vinegar stood there; so they put a sponge full of the vinegar on hyssop and held it to his mouth. When Jesus had received the vinegar, he said, ‘It is finished’; and he bowed his head and gave up his spirit” (Jn. 19:28-30).
The “it” that was now finished or consummated was the Passover that Jesus had begun—but interrupted—in the Upper Room. Its completion was marked by Jesus’ drinking the sour wine, the fourth cup.
In other words, what was finished was Jesus’ fulfillment of the Old Covenant Passover as He transformed it into the New Covenant Passover. Here we see how the Passover, Christ’s sacrifice, and the Eucharist are all intimately related (see generally, Catechism of the Catholic Church, nos. 1362-72).
Now we too are called to receive Jesus in Holy Communion, which unites us with Christ and with one another in the worldwide (“catholic”) family of God.