Walls that begin within 10 1/2” (27 cm) of the ground and extend upward to at least 40” (1 m) above the ground arekosheraseruvwalls.
Wearing Watch with No Eruv
You may not wear a non-decorative watch on Shabbat where there is no eruv or if you have the custom of not relying on eruvs. If you would wear your watch as a piece of decorative jewelry even if it did not work, you may wear it on Shabbat even without an eruv.
Shabbat: Dog-Walking outside Eruv
You may walk a dog or other animal on a leash on Shabbat outside a private domain, but you must hold the leash within 10 1/2" (27 cm) of the end and no part of the leash may droop to within 10 1/2" of the ground at any time.
Shabbat: Dog-Walking inside Eruv
You may walk a dog or other animal on a leash on Shabbat within an eruv or inside an enclosed property.
Wearing Collar Stays with No Eruv
You may wear collar stays on Shabbat even where there is no eruv.
Using Cane, Crutches, Wheelchair outside Eruv
You may use a cane, crutches, or a wheelchair if any of these are needed on Shabbat, even without an eruv.
Carrying Children on Shabbat outside Eruv
You may not carry children on Shabbat in a public domain without an eruv. Situation An eruv breaks or is down onShabbat. What To Do Do not tell someone who is carrying a child, pushing a stroller, or in a similar situation that theeruvis down. NOTE If a person is not carrying a child, pushing a stroller, etc., tell him or her that theeruv is down.
Shabbat: Ball Playing in Yard or Eruv
If a private yard is enclosed, playing ball is not forbidden. Within a city eruv, do not play ball.
Slope of Body of Water for Eruv
A body of water may be an eruv border if the land:
Slopes down into the water 40 inches or more, and
Is more than 25 degrees from horizontal.
If You Do Not Use the Eruv
If you do not normally carry on Shabbat even in an area with an eruv, you may not ask another Jew to carry something for you. But if the other Jew does carry an item, you may use it.
Jewish Festivals and Ball Playing in Yard or Eruv
Playing ball is not forbidden on Jewish festivals, as long as the Jewish festival does not coincide with Shabbat (in which case, it is not forbidden to play ball in an enclosed private yard, but it is not in the spirit of Jewish festivals or Shabbat).
Introduction to Eruvs
An eruv forms a boundary around an area of land in order to create a private domain (reshut ha'yachid). Carrying items within that domain is permitted on Shabbat. The eruv boundary may include a variety of structures such as:
Real physical structures—whether natural (such as tree trunks, bushes) or man-made (buildings, fences, cars);
Natural topographic features (such as slopes); and/or
Presumptive doorways (often made of poles and wires or strong string).
Solid or Halachically Solid
Two structures (regardless of how thick or wide they are) within 10.5 inches of each other are considered to be halachically solid and constitute a single structure; this is called lavud. NoteA halachically solid wall may have gaps of more than 3 tefachim (10.5 in.) high or wide (i.e., in either dimension) as long as the other dimension is less than 3 tefachim wide.
Examples
A halachically solid wall can be made of a:
Wide mesh of ropes or strings; the cross strings are very far apart, as long as the vertical strings are within 10.5 inches of each other.
Picket fence; each vertical slat must be within 10.5 inches of the adjacent slat OR each horizontal piece that connects the vertical slats must be within 10.5 inches of the adjacent horizontal piece.
Chain-link fence.
Height
All vertical eruv components must be at least 40 inches high. There is no maximum height for the eruv if it is a halachic doorway (tzurat ha'petach--two uprights and a horizontal bar above and connecting the two).
Width
A solid component (for example, a board, wall, house, etc.) must be at least 12 inches from side to side.
Non-solid components (for example, a series of narrow bushes, a series of trees with trunks less than 12 inches across, various types of fences, etc.) must be within 10.5 inches of each other and of the ground, both horizontally and vertically, for the entire distance between adjacent trees/bushes. They must be at least 40 inches high or wide.
Connectors
Vertical components, such as poles, that are connected above or below in the following ways are also halachic walls, regardless of how far apart they are:
Connected above, such as with a board or string that rests across the tops of vertical poles, and which are at least 40 inches above the ground at all points along its course, or
Connected below within 10.5 inches of the ground, such as bushes or small trees with branches that come within 10.5 inches of the ground at all points (even at the attachment point to the trunk). Components must reach up to at least 40 inches above the ground.
Thickness of Lechi
A lechi for an eruv may be of any thickness and any width; even a string or wire may be used, as long as it is sufficiently tensioned so as not to wave in the wind.
Incline of Lechi
Alechi for an eruv must be less than 45 degrees from vertical.
Shabbat: Bioluminescence
You may use bioluminescent light on Shabbat and you may carry the light within an eruv or a building (if it is permitted to carry there), but you may not activate it on Shabbat.
