eruv

An eruv is a boundary that halachically transforms a group of private spaces into one larger private domain for Shabbat and certain festival days. In Jewish law, carrying from a private domain to a public domain on Shabbat is restricted. An eruv enables carrying within the defined area by treating the entire enclosure as a single private domain.

There are two main forms. Eruv chatzeirot (enclosing courtyards) unites adjacent private spaces such as homes and yards within a shared boundary. This boundary can be a physical wall or fence, or a symbolic enclosure called a tzurat hapetach, created with posts and a cord or chain to suggest a doorway. Eruv techumin extends the permitted Shabbat walking distance by establishing a boundary around a city or neighborhood, effectively including nearby areas within the eruv.

Establishing an eruv typically requires a competent halachic authority. The boundary is defined, publicized, and maintained by the community; it often relies on existing walls, fences, or street lines, supplemented as needed with tzurat hapetach markers. Regular checks ensure the boundary remains intact and valid.

Limitations and scope. An eruv does not legalize prohibited activities outside its boundary, nor does it apply to all communities. It is a rabbinic mechanism and can be altered or dissolved by competent authorities if safety, geography, or halachic considerations change. In practice, eruvim are common in many urban areas and some suburban neighborhoods, where volunteers and clergy coordinate to sustain the boundary for Shabbat observance.