Exodus chapter 11 records the Tenth plague against the Egyptians. This plague was a destruction of the first-born of all those who did not put the blood of a lamb over the door of their house. This final plague convinced the Pharaoh to release the Israelites from Egypt in order for them to return to the land God had promised them.
In the original observance of passover, the passover lamb was killed and the blood smeared with a hyssop branch on the doorposts of the family's home. (Exodus 12:21-22) These instructions for the observance of the passover must have a future orientation, since the original Passover was one night and this instruction for observance is to be practiced over seven days. (Ex 12:15) The flesh of the lamb is eaten along with unleavened bread. (Ex 12:8) It appears that only later was wine added to this ritual. Eventually four communal cups were used and passed around for the family to drink. Eventually, a dispute arose over whether to have four or five cups. A compromise came that four cups were used, and a fifth was set for Elijah. This is sometimes thought to be a proxy for Moses or that Elijah is prophesized to come before the Messiah, adding an element of eschatological hope of a future redemption to the meal. Each Passover, the Jews were reminded that though they celebrated a past deliverance, they also looked forward to a greater future hope in the Messiah.
The Gospel writers all seem to present the Lord's Supper as happening during the time of Passover. Luke 22:8 records Jesus giving the instructions to his disciples to “prepare for us the passover that we may eat it.” Most commentators assume that if the four cup ritual was in use at the time of Jesus, that his words relating the Passover elements to himself come with the third cup, a thanksgiving to God for bringing forth the fruit of the vine.
Supper in the time of the Passover: The Hallel passages of the Psalter were typically sung in the passover season (pss 113-118). Hence, since these songs were in the minds of the Jews, Christ was greeted by these words (Ps. 118:25) when he entered Jerusalem. (Matt 21:9) Although we can not be certain as to the significance of this selection from a Passover psalm in the minds of the children, the author of the gospel of Matthew certainly expected the connection to be made with his Jewish audience that this was a song sung during the celebration of passover and it anticipates Christ.
Paul most clearly makes the connection, when in 1 Corinthians 5:7 he refers to Christ as “our passover, sacrificed for us.” Christ is anticipated in the lamb, for only after atonement would the celebratory section of the meal begin. In taking the elements of the meal, Christ also infuses meaning into these portions of the meal as well. Christ associates the bread with his body (Luke 22:19) and the wine with his blood. (Luke 22:20) Although we did not see the wine or bread as anticipating directly Christ's coming before Christ, after the institution of the Supper in the Gospels, we now do.
The Passover can be seen to anticipate Christ in two important ways. First, the lamb whose blood redeems the covenant family points to Christ's sacrifice. Second, the meal looks towards a celebratory event. The celebratory nature of the meal in light of reconciliation should be instructive. Jewish practice was not a solemn mournful meal, but a celebration of the reality of what comes after atonement, forgiveness and resurrection.