Having established that the Pesach (Passover) sacrifice could be eaten "in two places" by a single group, Rabbi Shimon ben Yochai was asked the obvious follow-up question: how exactly does that work in practice?
He offered two vivid scenarios drawn from everyday life in ancient Israel. In the first, a group is eating the Passover lamb inside a house when the roof suddenly collapses. The group moves outside to the courtyard and continues their meal. They have now eaten in two places — inside and outside — but they remain one group. The meal is valid.
In the second scenario, the group begins eating in the yard when rain starts to fall. They pick up and move indoors. Again, two physical locations, one unbroken group. The meal is valid.
These examples are deliberately mundane. Rabbi Shimon ben Yochai chose collapsing roofs and rainstorms — not exotic or unlikely events, but the kind of ordinary disruptions that actually happen during meals. His point was that the Torah's law was designed for real life, not ideal conditions. The commandment to eat "in one house" was never meant to chain people to a crumbling building or force them to sit in the rain.
The underlying principle is resilience. Sacred meals are not invalidated by accidents or weather. What holds the Pesach together is not the structure overhead but the intention of the people eating it. As long as the group stays together, the place can change. Holiness travels with the community, not with the building.