I. One of the interesting though less well known customs of Passover is to leave the doors of one’s house unlocked all night. The custom is tied to the fact that the night of the liberation is referred to as leil shimurim/night of vigil or watch in Exodus (12:42): “It is a night of watch [leil shimurim] for the Lord, for taking them out of the land of Egypt, this night is the Lord’s, a watch [shimurim] for all the Israelites through their generations.” (Robert Alter’s translation.) The word shimurim, whose only biblical appearance is in this verse, can be understood in the sense of preserving, or waiting for; or in the sense of guarding or being guarded. The custom of leaving the doors unlocked is tied to this latter sense of being guarded. The night of Passover is a night that is guarded or protected for all the children of Israel, and therefore the security of a locked door is superfluous.

This custom reflects and ties together some of the major themes of the holiday. 

The final plague which God inflicted upon the Egyptians was the killing of the first born sons. Prior to this plague, God had ordered the Israelites: “None of you shall go outside the door of his house until morning.” (Exodus 12:22) Then “in the middle of the night” God killed all the Egyptian first borns. Why were the Israelites forbidden to leave their houses during the hour of destruction? Rabbi Aharon Shmuel Tamares (1869-1931) says that the reason is so that the Israelites would not be involved in the cycle of violence. Only God, Godself would put an end to the structures of an oppressive society. God would extract vengeance but Israel would not. The cycle of violence—first oppression and then vengeance—would be disrupted. Israel would be free to live outside of this cycle, with no need of vengeance. This was the dream.