The Passover was instituted by the Lord as a remembrance meal, that is, to re-present the miraculous deliverance He gave to His people, Israel, in leading them out of the bondage to Pharaoh and the idolatrous gods of Egypt so that He could serve them. Every year, on the 15th of the first month of the year, the Israelite families had to slaughter and consume an unspotted Passover lamb.
But there were other ceremonies, too. Among these was the Lord's command to choose and separate from the flock the lamb to be sacrificed. On the 10th of the first month of the year, the unblemished lamb was chosen and kept until the fourteenth day of the month. And when evening came on the fourteenth, it was slaughtered, roasted, and eaten.
Along side of this, the rabbis record that the chosen Passover lamb was to be tied up on the 10th, after it had been chosen, and remain bound before the eyes of all the Israelites for the full four days until it was slaughtered.
John the Baptist tells us who our Passover Lamb is. Pointing to Christ our Lord, he says, "Behold the Lamb of God, who takes away the sins of the world." Jesus is our unblemished, Passover Lamb. He fulfills in His Passion the entire Passover Feast. He is slaughtered and roasted in the Father's wrath against sin on the cross. None of his bones are broken. And His shed blood, when applied, is a sign of life so that the Angel of Death passes by.
And today, five days before the thorns, the nails, and the spear, the Lamb of God, Jesus Christ, according to the Lord's command, is separated from the flock, placed on a donkey, and paraded into Jerusalem through the Sheep's Gate with the acclamation: "Hosanna," that is, "Save us, now, O Lord." And He would. He
For when He entered the city, Jesus our Passover Lamb of God, is bound and set on display before all the people for the next four days. He is first bound in the Garden of Gethsemane, after having been betrayed with a kiss. He remains bound then in the house of Ananias and that of Caiaphas, and then before Pilate, the governor of Judea. All this that the Scripture might be fulfilled. (The preceding paragraphs adapted from Gerhard, Postilla, Vol. 1, 284-285.)
And why does Jesus our Passover Lamb of God do this? For the same reason, that the first Passover was observed: To save us from our slavery and idolatry.
But we have never been slaves. We are free. And we have always worshipped the true God, the holy Trinity.
Jesus says, "Whoever sins is a slave to sin." And the apostle James, does he not say, "For whoever keeps the whole law but fails in one point has become accountable for all of it"? For when you break any commandment, you break all of the commandments. So you have broken the first commandment: You shall have no other Gods. Which means you have another God. You are an idolater. You have feared, loved, and trusted in something other than one, true God, the Holy Trinity. Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived: neither the sexually immoral, nor idolaters, nor adulterers, nor men who practice homosexuality, nor thieves, nor the greedy, nor drunkards, nor revilers, nor swindlers will inherit the kingdom of God."
And such were some of you. You have not kept all the commandments, perfectly, all the time and in ever circumstance. Repent. And "Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry."
But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God. For the Passover Lamb of God, who takes away the sin of the world, though He died, yet does He live. He was roasted in the Father's wrath on the cross. He shed His blood to make you clean, to forgive your sin, to mark you for life and save from death. What we could not fulfill according to the Lord's command. Jesus has fulfilled in accordance with the Lord's command.
You are delivered from bondage to sin and death and idolatry. For Jesus is the Passover Lamb.
And having been set apart, bound and put on display before all the people; having been slaughtered and roasted on the cross, He gives you His flesh to eat and His blood to drink. This is in remembrance of Him, to re-present, to give to you now what He won for you then: the forgiveness of sins, eternal life, and salvation. Blessed is He who comes in the name of the Lord. Hosanna in the highest. Come and save us Lord. He is come, bearing salvation in His body and His blood. Take eat, take drink: The Passover Lamb of God given for you.