Many of the laws and customs that shape the observance of Shabbat are widely known, like lighting candles on Friday afternoon or the general prohibition of doing various forms of “work.” Beyond these well-known practices, however, lie numerous lesser-known laws. One such law is techum Shabbat, the “Shabbat boundary.”

Techum Shabbat defines the allowable distance one may walk outside an inhabited area on Shabbat. As a rule, one is limited to 2,000 cubits, with certain important caveats.

At times, this boundary can be expanded by placing an eruv techumin (essentially a symbolic Shabbat meal) at the end of this area.

The unit of measurement used in this conversation is known as an amah (amot plural) in Hebrew, and a cubit in English. An amah is the approximate length of a man’s arm, measured from the elbow to the tip of the middle finger—between 18 and 19 inches.

So 2,000 amot is just under 3/5 of a mile, or a single kilometer. And four amot is just over six feet.

The Source for Techum Shabbat

Techum Shabbat is codified as a Rabbinic injunction by Rabbi Yaakov ben Asher in his seminal work Arba'ah Turim.1 The Biblical verse, “Let no man go out of his place on the seventh day,”2 hints to this law, he writes.3

Maimonides, however, interprets the verse as a Biblical prohibition against walking further than 12 mil (1 mil is equal to approximately one kilometer) on Shabbat.4 He maintains that the Rabbinic stipulation that one go no further than 2,000 amot (approximately one mil) is simply to safeguard the Biblical prohibition.5 Maimonides’ ruling is based on the law as codified by the Jerusalem Talmud.6

Ultimately, all codifiers agree that the 2,000-cubit boundary is a Rabbinic one; the question is only if we take into account the Jerusalem Talmud, which records a Biblical restriction of 12 mil.

Where Is the Techum Measured From?

If you were out in an open field, you’d be allowed to walk 2,000 cubits from the edge of the four cubits considered your personal space—the approximate amount of space a person takes up when lying down with their arms and legs outstretched. This space is squared off, and one may walk 2,000 amot in any direction from its edge.

The 8 cubit square granted to a person as his Shabbos limits - Sichos in English
The 8 cubit square granted to a person as his Shabbos limits
Sichos in English

If, however, one was in a house—even outside of a city—the 2,000 limit would start from the edges of that dwelling. Again, it would be squared off using its furthest points, and the 2,000 limit is measured from the edges of that square.

The Shabbos limits of a round city - Sichos in English
The Shabbos limits of a round city
Sichos in English

Additionally, any settlement consisting of dwellings grouped together is considered an expansion of one’s personal space. As such, the 2,000 cubit boundary would only begin beyond the city’s limits. Again, the city is squared off, and the limit is measured from the edges of the square. This applies even if there is no wall surrounding the city.7

Now, where does a city end? The boundary is not defined by municipal or state law, but by the continuous presence of houses. Any dwelling within 70.66 amot of the last dwelling extends the city, meaning that the 2,000 cubits are now measured from that dwelling. So it may even be possible to walk from one city to another if there is a dwelling within every 70 amot between the two.8 In other words, cities that are connected to each other are considered one city for the purpose of techumin.

The two opinions regarding the point from which the Shabbos limits of a city are measured when there is a house within 70 2/3 cubits of the city - Sichos in English
The two opinions regarding the point from which the Shabbos limits of a city are measured when there is a house within 70 2/3 cubits of the city
Sichos in English

Measuring techum Shabbat is not for the faint of heart. A high level of expertise is required, and it is really a job for a qualified rabbi. However, here are some pointers. First, you’ll need to identify the furthest dwelling in each direction and draw a square around them. Next, you’ll need to measure 2,000 cubits from each side of this square.

You must also account for geographical features such as hills, valleys, rivers, etc. The boundary is not “as the crow flies,” but as a person walks, so that it follows the contour of the land.9

Eruv Techumin: How Can Techum Shabbat be Extended?

What happens if you need to walk to a place that is, say, 3,000 amot from the edge of your town?

In certain scenarios,10 one may extend the limit from 2,000 to 4,000 amot by establishing an “eruv techumin,” a Rabbinic construct that entails depositing enough food for two meals at the 2,000-cubit limit. Doing so demonstrates that this location is the person’s Shabbat “dwelling.” The food’s placement indicates where the person “resides” at the commencement of Shabbat, even if they are physically elsewhere, allowing them to walk 2,000 cubits from this new base in all directions.11

A properly placed eruv allows you to walk 4,000 cubits in one direction, but restricts your ability to move 2,000 cubits in opposite directions. For instance, if an eruv is placed 2,000 cubits to the east of your location (or 2,000 cubits from the eastern boundary of a city), you can move 2,000 cubits from that point. However, you cannot move any distance beyond your location to the west (or beyond the city’s western boundary).12

What Happens if a Person Breaches the Techum Shabbat?

If a person willfully steps even one cubit outside the limit, they may not re-enter. They must remain within a four-cubit area from where they are standing. Even if the four cubits overlap with the original 2,000, they cannot return and consider it as if they had not left.13

If they left in a permitted manner due to extenuating circumstances, or if they left their limit unintentionally, they must stop walking immediately (when possible). If their four-cubit area intersects with their original Shabbat limits, it’s considered as if they have not left. They can return to the original area and move 2,000 cubits from their point of origin in all directions. However, if they now find themselves more than four cubits from the border of their initial permitted area, they may not re-enter and must remain within their current four-cubit space.14

To save someone’s life, you may leave the boundary, and the rabbis instituted further leniency and granted the life-saver 2,000 amot from where they find themselves after completing the life-saving measures.15

The Spiritual Component

The Rebbe drew a lesson from the laws of techum Shabbat to our Divine service of G‑d. The verse used as the source for (or at least a hint to) the concept of techum Shabbat, “Let no man go out of his place on the seventh day,”16 speaks to the fact that the Jews in the desert were to stay within the Israelite camp.17

That is our place too—a camp centered around the “Tent of Meeting” and surrounded by the “Clouds of Glory,” which shield us from foreign influences. In every circumstance, a Jew must stand firm to his or her Torah principles. Even when venturing into the outside world, we must ensure that we remain within the realm of holiness.18