The final plague to strike Egypt was also the most devastating. God had warned Pharaoh that if he didn't acquiesce to the requests made by Moses and Aaron on His behalf, Egypt would pay the ultimate price; the death of all its firstborn.
But Pharaoh refused to yield. To give in and grant Moses and Aaron’s request at that point would be tantamount to admitting defeat, to admitting that he had, in fact, been wrong and that was not something he was willing to do.
So he defiantly dug in his heels and refused to let the Israelites go. It was then that God directed Moses to prepare His people for the coming storm of grief and loss. The Israelites were told that the angel of death would scour the length and breadth of the land that very night. They were instructed to take a lamb, a young, unblemished lamb, and kill it, then to take its blood and smear it over the lintel and doorposts of their homes.
Moses assured them that all those whose homes were covered by the blood of the lamb would be spared the stroke of the angel’s sword. The blood of the lamb would cause the angel to pass over them.
This would be the first Passover. A festival that has been celebrated by Jews for over three thousand years, not only remembering God’s miraculous deliverance from slavery but also remembering that He spared his people from the finger of death because of the blood of the lamb.
That night the angel of death went through the land of Egypt and took the lives of all the firstborn. Every firstborn that was not under the protection of the blood of that paschal lamb. That lamb was a symbol of Jesus, the ultimate Lamb of God who would take away the sins of the world and protect us from the final destruction of the wicked described in the Bible.
When the first keening wails of grief spread across the land, gouging out the hearts of its inhabitants Pharaoh came face to face with the cost of rebellion. The very real cost of turning up his heel against the God whose hand curled around the breath in his body