Halachah 1 — Closed and Open Lanes
The Rambam begins by defining two types of lanes:
- A closed lane has three walls.
- An open lane has only two opposite walls, allowing passage through both ends.
This distinction is fundamental, because the requirements to permit carrying differ greatly depending on whether the lane already has three sides enclosed or remains open on both ends.
Halachah 2 — Permitting a Closed Lane
To permit carrying in a closed lane, one must add a minimal structure on the fourth side:
- either a pole (lechi), or
- a beam (korah) across the entrance.
According to Torah law, three walls are sufficient to define a private domain. The requirement to add a fourth boundary is Rabbinic. Therefore, the Sages allowed a minimal symbolic structure to suffice, treating it as if the fourth side were closed.
Halachah 3 — Permitting an Open Lane
For an open lane (open on both ends), a stronger arrangement is needed:
- a frame of an entrance (tzurat hapetach) on one end, and
- a pole or beam on the other.
An L‑shaped lane is treated like an open lane. The idea is that since the space resembles a passageway, additional enclosure is needed to transform it into a space suitable for carrying.
Halachah 4 — A Natural Boundary Can Replace a Lechi or Korah
If a lane slopes downward or is otherwise clearly distinct from the public domain, it does not require a pole or beam. The natural difference itself serves as a recognizable boundary.
This reflects a recurring principle: clear visual distinction can substitute for constructed markers.
Halachah 5 — Ends at Natural Barriers
If one end of a lane reaches the sea and the other reaches a permanent garbage dump, no additional structure is needed.
These features are considered stable and unlikely to change, and thus function as permanent boundaries.
Halachah 6 — Lane Ending in a Courtyard
If a lane opens into the middle of a courtyard and not directly opposite its entrance, it is treated like a closed lane and remains permitted.
If it opens into the side of a courtyard, however, carrying is forbidden.
Even when the courtyard belongs to a single person, restrictions apply, because future changes (such as construction) may alter the configuration and invalidate the arrangement.
Halachah 7 — Conditions for Using a Pole or Beam
A lane may be permitted through a pole or beam only if:
- multiple courtyards or houses open into it,
- it is at least four cubits long,
- and it is longer than it is wide.
If length equals width, it is considered a courtyard rather than a lane and requires stronger measures (multiple poles or a wider partition).
Halachah 8 — Courtyard vs. Lane
If a courtyard is longer than it is wide, it is treated like a lane and requires a pole or beam.
If a lane lacks multiple courtyards or sufficient length, it is treated more strictly and requires more substantial enclosure.
This shows that classification depends not only on structure, but also on use and layout.
Halachah 9 — Narrow Lanes and Nature of Lechi vs. Korah
If a lane is less than three handbreadths wide, it is considered closed and needs no structure.
The Rambam distinguishes between:
- a beam (korah), which serves as a symbolic marker,
- a pole (lechi), which is considered an actual wall.
Therefore, throwing into a lane with a beam does not incur liability, while a lane with a pole may be treated as a true private domain.
Halachah 10 — Making a Public Domain Permissible
To permit carrying in a true public domain, a far stronger measure is required:
- gates must be erected at both ends.
A simple frame, pole, or beam is insufficient. The Torah-level severity of a public domain requires a more substantial enclosure.
Halachah 11 — Area Under the Beam
It is generally permitted to carry under the beam or opposite the pole at the entrance of a lane.
However, if the adjacent area is a carmelit, this area becomes restricted unless an additional marker is added. This is because adjacent neutral areas combine and take on the stricter classification.
Halachah 12 — Materials for a Pole
A pole may be made from almost any material, even:
- a living creature,
- or an object from which benefit is normally forbidden.
Since there is no minimum width requirement, formal physical usability is not essential—only its presence and form.
Halachah 13 — Requirements for a Beam
A beam must be at least one handbreadth wide and strong enough to hold a standard brick.
Unlike a pole, it must meet a structural standard, and certain forbidden objects (like idolatrous trees) cannot be used.
Halachah 14 — Size Limits of Openings
For a beam or pole to be effective:
- height must be between ten handbreadths and twenty cubits,
- width must not exceed ten cubits,
unless a frame of an entrance is used, in which case much larger openings are allowed.
Halachah 15–16 — Visibility and Height Adjustments
A beam higher than twenty cubits is invalid unless it is decorated so that it is noticeable.
If the lane is too tall, a beam must be placed lower. If too low, the ground may be dug out to reach the required height.
This reflects the principle that a beam must serve as a visible boundary marker.
Halachah 17 — Side Openings
If a side opening exists near the entrance:
- it is acceptable if part of the wall remains,
- otherwise, carrying may be forbidden unless the opening is small.
Openings are evaluated based on width and remaining wall structure.
Halachah 18 — Lane Passing Through a Courtyard
If a lane passes entirely through a courtyard into the public domain, it is treated as an open lane and is restricted.
However, the courtyard itself retains its private domain status.
Halachah 19 — Multiple Paths to a Lane
If several paths lead from the public domain into a lane, the lane becomes equivalent to an open lane.
To permit carrying:
- each entrance must have a frame,
- and one end must have a pole or beam.
Halachah 20–22 — Placement of Poles
The position of a pole determines which part of the lane is permitted.
Poles may:
- project outward,
- be pre-existing structures,
- or be visually distinct from one side only.
However:
- gaps larger than three handbreadths invalidate them,
- very wide poles may be treated as walls instead.
Halachah 23–26 — Complex Beam Cases
The Rambam discusses many technical configurations:
- beams covered or hidden,
- beams not fully reaching across,
- multiple beams working together,
- crooked or curved beams treated as straight.
The key principle is that the beam must function as a clear, visible boundary.
Halachah 27–30 — Special Enclosure Around Wells (Pasei Bira’ot)
A unique leniency allows minimal corner partitions around wells to permit animals to drink.
Requirements include:
- partitions at each corner,
- defined distances between them,
- limited to public needs (such as pilgrims).
These structures are treated as valid enclosures despite large openings, due to special Rabbinic leniency.
Halachah 31–34 — Limitations of the Leniency
This special structure applies only in specific circumstances:
- primarily in Eretz Yisrael,
- primarily for public use,
- particularly for water access.
If conditions change (such as the well drying up), the permission is revoked.
The Rambam consistently shows that the leniency is tied to necessity, not general use.
Halachah 35 — Roofed Areas and Broken Corners
An area with three walls and a roof may be treated as enclosed due to the principle that the roof’s edge is considered to descend.
However, a corner opening in a structure is not treated as a doorway and invalidates carrying unless corrected with a beam.
Halachah 36 — Measurement Standards
The Rambam concludes with measurement rules:
- a handbreadth = four fingerbreadths
- a cubit = six handbreadths
Some measurements are taken tightly, others more loosely, depending on whether the law requires stringency.