The history of Passover
The book of Exodus describes how the Jews lived in oppression in Egypt for 430 years.
Then Moses, a Jew who had been raised as a prince in Pharaoh’s household, learned his true identity and witnessed the cruelty meted out to Jewish slaves by Egyptian masters. Moses was commanded by God to demand freedom for the Jews from Pharaoh. Pharaoh refused to allow the Jews to leave Egypt several times, provoking devastating plagues such as swarms of locusts and three days of darkness. Finally, God threatened to kill the firstborn son of each Egyptian family if Pharaoh again denied liberation to the Jews.
When Pharaoh did refuse again, God instructed Moses to have the Jews ready themselves for a hasty departure from Egypt. Before leaving, however, all Jewish families were to prepare and eat a sacred meal. Strict rules governed the cooking and consumption of the meal, and thereafter a festival meal that adhered to these guidelines was to be observed by the Jews “generation after generation as a rule for all time.”
The blood of the animal killed for the meal was to be smeared over the doorway of each Jewish household. The night following the meal, God would move through Egypt, killing the firstborn “of every man and beast” in each household as retribution for the enslavement of the Jews. However, God promised, He would “pass over” the lintel of the doorway of any home that was covered with the sacrificial blood. This was the first pesach, Hebrew for Passover.