Mishneh Torah, Sabbath 28

Hook

What if the "borders" of your world weren't fixed by walls or maps, but by the physical reach of your neighbors? In Maimonides’ architecture of the Sabbath, a city is not a static object; it is a living, breathing entity that expands whenever a new home is built within its orbit, effectively re-drawing the map of where you are permitted to walk each week.

Context

This passage deals with the techum (Sabbath limit), the 2000-cubit radius within which one is permitted to travel on Shabbat Mishneh Torah, Sabbath 27:1. Maimonides draws heavily on the tractate of Eruvin 55b–59a, which grapples with the transition from the "city" to the "wilderness." A vital historical note: these laws were not purely theoretical; they were essential for communal life in the Diaspora. If a city were defined too narrowly, the community would be effectively imprisoned; if too broadly, they would risk violating the Rabbinic prohibition against traveling beyond the techum. The "seventy and two-thirds cubits" mentioned here is derived from the karpef (the enclosure of the Tabernacle courtyard), anchoring modern urban geography in the ancient dimensions of the desert sanctuary.

Text Snapshot

"Whenever there is a home that is outside a city, but seventy and two thirds cubits... or less from the city, it is considered to be part of the city and joined to it. When two thousand cubits are measured in all directions from the city, this house [is considered to be on the extremity of the border] and the measurement [begins] from there." Mishneh Torah, Sabbath 28:1

"If one house is within seventy cubits of a city, another house is within seventy cubits of the first, and a third within seventy cubits of the second [and so on], they are all considered to be one city, although the chain extends for a distance of several days walk." Mishneh Torah, Sabbath 28:1

Close Reading

Insight 1: The Calculus of Connectivity

Maimonides establishes a fractal-like logic for the city. The city is not defined by its municipal borders or its history, but by the "chain" of human habitation. The rule that one house connects to the next, provided they are within 70 and 2/3 cubits of one another, creates an "urban sprawl" that is entirely legalistic. If you have a string of houses stretching for miles, the halakhic "city" stretches with them. This reveals a profound tension: the law prioritizes human proximity over territorial permanence. The city exists wherever people are close enough to be considered "neighbors."

Insight 2: The Definition of "Dwelling"

Note the rigorous distinction between a "dwelling" and a mere "structure." Maimonides explicitly excludes graves, cisterns, and ships from extending the city's borders Mishneh Torah, Sabbath 28:2. Why? Because the techum is fundamentally about where people live. A synagogue or a bridge only counts if it contains a dwelling. This suggests that for Maimonides, the "city" is defined by the domestic sphere—the place where one eats, sleeps, and exists in a state of residency. The architecture of the Sabbath is essentially an architecture of home-making. If you don't live there, it doesn't "count" as part of the community's footprint.

Insight 3: The Geometry of Human Error

Maimonides spends significant energy on the mechanics of measurement—ropes of flax, the exclusion of shorter or longer ropes to prevent stretching, and the need for experts Mishneh Torah, Sabbath 28:12, 19. Yet, he is surprisingly lenient when experts disagree. If two experts offer different measurements, we follow the one that is more lenient because the techum is a Rabbinic institution. This is a fascinating structural choice: the law demands mathematical precision in the method (the rope, the plumb line), but it demands a bias toward freedom in the outcome. We measure with a rigid standard, but we interpret the results with a generous heart to ensure the community isn't unnecessarily restricted.

Two Angles

The debate over the "70 and 2/3 cubits" extension—often called the karpef—highlights a classic conflict between the Rambam and his predecessors. The Ohr Sameach points out that the Yerushalmi Eruvin 5:2 records a debate between Rabbi Meir and the Sages. Rabbi Meir argues that the city is automatically granted this extension regardless of proximity to other houses, while the Sages argue it is only granted if there is a house within that distance. Maimonides sides with the Sages, insisting that the city’s expansion must be earned through the presence of another dwelling. He rejects the idea that a city possesses an inherent, "magical" buffer zone; it must be tied to the reality of the surrounding, inhabited world.

Practice Implication

This halakhic framework teaches us that the "boundaries" of our community are often more fluid than we assume. In modern decision-making, we often treat borders as fixed: "This is our group; that is the other." Maimonides reminds us that inclusion is a matter of proximity and connection. If we are within reach of one another, we are, in a very real sense, one entity. This shapes daily practice by encouraging us to look for the "in-between" houses—the people or groups on the fringes—and recognizing that by bridging the gap, we expand the reach and the capacity of the entire community.

Chevruta Mini

1. If the city is defined by a chain of houses, does this imply that a city could technically encompass the entire world if the houses are placed close enough? What does this tell us about the limit of "community"?
2. Maimonides relies on the "expert" to determine the border, yet allows for testimony from a child or servant to expand it. Why would the law trust a child’s memory over an expert’s measurement?

Takeaway

The Sabbath limit is not a wall intended to confine us, but a living, expandable boundary that grows whenever we choose to settle near one another.