The Torah instructs that when preparing for the Paschal lamb, if a household is too small to consume the entire animal, they should share it with "the neighbor near his house" (Exodus 12:4). The Mekhilta digs into this phrase with the precision of a legal mind: how near does "near" mean?
Could "near his house" include a neighbor who lives in the same building but in a different domain — say, someone on a shared roof with a separate entrance? The rooftops of ancient Israel were social spaces. Neighbors on adjacent roofs might know each other well. But the Mekhilta rules that physical proximity alone is not enough. The Torah specifies "near his house," meaning in the same residential domain, not merely in the same physical structure.
This seemingly minor distinction carries real practical weight. The Passover lamb had to be consumed in a single location by a defined group. If the membership could extend to anyone in a loosely connected building complex, the boundaries would blur. The Mekhilta tightens the definition: your Passover partner must be a genuine neighbor, someone whose dwelling space is functionally connected to yours.
The ruling reveals how carefully the rabbis read every word of the Torah's Passover legislation. "Near his house" is not a throwaway phrase — it is a legal boundary marker. It ensures that the Passover group is truly a community of proximity, not just a random collection of people who happen to share a structure. The intimacy of the Passover meal demands that the participants actually live as neighbors, not merely exist in architectural adjacency.