Targum Pseudo-Jonathan on Exodus (Exodus 23:18) gives the Pesach offering a particular constraint: Sons of Israel My people, while there is leaven in your houses you may not immolate the bloody sacrifice of My Pascha; nor shall the fat of the sacrifice of My Pascha remain without the altar until morning, nor of the flesh that you eat in the evening.
Three rules layered together. First, no chametz can be in your house when you slaughter the lamb. Second, the fat portions must be burned on the altar that night, not left until morning. Third, the meat itself must be eaten by morning — none may linger.
Why Everything Must Happen That Night
The Pesach offering is not a leisurely ritual. It re-enacts a night of urgency — the night Israel ate standing up, staff in hand, sandals on, waiting for the word to move. The Torah preserves that urgency in every detail. Chametz, the slow bread, the comfortable bread, cannot share the house with the lamb. Leftovers are forbidden. Morning cannot find any trace of the meal.
This is why Pesach, alone among the festivals, is defined by what is absent. No leaven. No delay. No remnant. The holiday preserves the shape of a crisis that has already been survived, so that survival stays vivid.
The Takeaway
Some memories lose their power if they are stored too casually. The Torah designs Pesach to be eaten fast, burned fast, and ended by dawn — because a redemption experienced in haste must be remembered in haste.