For I will pass through the land of Egypt this night and will smite all the firstborn in the land of Egypt, both man and beast; and against all the gods of Egypt I will execute judgment. I am the Lord. The blood shall be for a token or sign to you upon the houses where you are, when I see the blood, I will pass over you, and no plague shall be upon you to destroy you when I smite the land of Egypt (Ex. 12:12-13).
The Lord God constituted Passover for Israel at the time when they left Egypt, as a memorial of their deliverance from bondage to Egypt and as a future signal pointing to YAHSHUA the Son of God, Who was to come as the perfect Lamb of God to be sacrificed for the sins of mankind. Before then, Jacob’s sons were not yet an established nation. They were residents in Egypt for many years, as in 430 years. God promised Abraham that after that frame of time, his descendants would leave for the Promised Land as He had promised him. When the new Pharaoh arose to power, who did not know Joseph, neither the background history why he and his brothers landed in Egypt, things changed for all of them. They no longer enjoyed the freedom they used to have, but were subjected to hard labor mercilessly. Theirs is a story of contrast: blessings and hardships, but God had a plan for the offspring of Abraham. Because Abraham believed God’s word, he was promised blessings upon him and his posterity. Choosing Moses with the help of his brother, Aaron to lead his people out of Egypt, God performed great miracles before Pharaoh through them to show Pharaoh that He was and is the only true God, above all the Egyptians’ gods. Pharaoh’s heart became hard with every judgment God sent to them, until the slaughter of all the males in the land of Egypt, for which Jacob’s sons’ families were sealed with the blood of the sacrificial lamb they had killed that day.