Then Moses summoned all the elders of Israel and said to them, “Go at once and select the animals for your families and slaughter the Passover lamb.Take a bunch of hyssop, dip it into the blood in the basin and put some of the blood on the top and on both sides of the doorframe. Not one of you shall go out the door of his house until morning.When the Lord goes through the land to strike down the Egyptians, he will see the blood on the top and sides of the doorframe and will pass over that doorway, and he will not permit the destroyer to enter your houses and strike you down. 
I must admit that I have always been fascinated with this event – that is the Passover – wherein the Israelites were shown how to escape the coming wrath. Hyssop, dipped in the blood of a slain lamb without blemish, raised to the top of the door frame, on which the blood was spread, and as it inevitably dripped to the ground, it was then placed on each side. Who among them saw? Who among them saw the blood for what it was: a type or a foreshadowing of what was to come? They were given a task to protect themselves from the immediate danger of the coming destroyer, but hidden within the task was an image and a hint at the mystery which was hidden for long ages past (Rm. 16:25).
Christ, our Paschal Lamb, has been sacrificed to protect us from the coming wrath by He who is both Savior as much as Destroyer, Merciful as much as He is the Judge (1Co 5:7). He, our Savior Lord, bore the cross, on which His unblemished body was broken and pierced, also, on which His blood was shed. A crown of thorns pierced His head and nails through both His legs and hands fastened Him to a punishment that He was undeserving of, yet this brought salvation to many, protection from the Destroyer and Judge. Jesus is that Lamb without blemish and He was slain; His blood shed from top to bottom and left to right. He is the fulfillment of the type from the Passover and the reconciliation of man to the Father.
When they had been instructed to place the blood on the door frame and consume the roasted Lamb, they were commanded to remember this day for generations to come and it was to be a lasting ordinance (Ex. 12:14). Just as the Israelites were commanded to always remember and recant the story of the Passover, are we not to also remember the Paschal Lamb, Jesus’ sacrifice? It is with joyous hearts that we celebrate and remember the day in which God offered protection from the coming wrath and, this, by Christ’s shed blood. For generations to come, we preach Christ crucified and hope through His blood; this is a lasting ordinance. O! How glorious indeed is the wisdom and sovereignty of our God. Amen.
 The Holy Bible: New International Version. 1996 (electronic ed.) (Ex 12:21–23). Grand Rapids, MI: Zondervan.