Eruv

An eruv ([(ʔ)eˈʁuv]; Hebrew: עירוב, lit. 'mixture', also transliterated as eiruv or erub, plural: eruvin [(ʔ)eʁuˈvin] or eruvim) is a ritual halakhic enclosure made for the purpose of allowing activities which are normally prohibited on Shabbat (due to the prohibition of hotzaah mereshut lereshut), specifically: carrying objects from a private domain to a semi-public domain (carmelit), and transporting objects four cubits or more within a semi-public domain. The enclosure is found within some Jewish communities, especially Orthodox ones.

An eruv accomplishes this by symbolically integrating a number of private properties and spaces such as streets and sidewalks into one larger "private domain" by surrounding it with mechitzas, thereby avoiding restrictions of transferring between domains. Often a group constructing an eruv obtains a lease to the required land from a local government.

An eruv allows Jews to carry, among other things, house keys, tissues, medication, or babies with them, and to use strollers and canes – all of which are otherwise forbidden from being carried outside one’s home during Shabbat, in the absence of an eruv.