Why do we need an Eruv?
There are “four domains” in terms of carrying on Shabbos:
- Reshut Harabim – “public domain”
- Reshut Hayachid – “private domain”
- Karmelit – public domain on a rabbinic level
- Mekom P’tur – lacks the dimensions of a private domain
(On Yom Tov, as opposed to Shabbos, it is permitted to carry in these areas without an Eruv)One of the 39 forbidden categories of melacha on Shabbos is called hotza’a, which literally means “taking out.” It is forbidden to carry or throw from one domain to another. For example, if a house is a reshut hayachid, and the street outside is a reshut harabim, it would be prohibited to pass or carry an object, through a door or a window, from inside out, or outside in.A separate prohibition is that of ha’avara daled amot b’rshut harabim, carrying on object four amot (approximately 6 to 8 feet) in a public domain. This means that, for example, if the street were a public domain, and carrying an object, whether by hand, or in a pocket of one’s clothing, more than four amot would violate this prohibition.It should be noted that articles of clothing while they are being worn are not subject to this prohibition. So, for example, to wear a hat on one’s head, or a scarf around one’s neck, or glasses, is permissible. However, it would be forbidden to carry any one of these items by hand rather than wearing them in the usual manner.One may carry within a private domain. For example, you may carry anywhere within your own house, or any private residence.
What constitutes a reshut harabim, a public domain? In order to qualify as a reshut harabim d’orayta, a public domain on a Torah level, there are certain requirements. The exact requirements are a matter of dispute between halakhic authorities.
What constitutes a reshut hayachid? In order to qualify as a reshut hayachid, the area must be at least 4×4 tefachim (a tefach is between 3 and four inches) and have at least three walls that are at least 10 tefachim tall (approximately 40 inches).
What is a makom p’tur? A makom p’tur, (literally, an “exempt area”) area that does not meet the minimum requirements of a reshut hayachid, by having less than an area of 4×4 tefachim, or less than 10 tefachim in height.
A carmelit is an area that does not meet the requirements of a Reshut harabim. On a biblical level, it is a reshut hayachid. On a Rabbinic level, however, it is treated like a reshut harabim, making it forbidden to carry within this area, or back and forth from a private domain.
The purpose of creating an Eruv is to convert an area that was a reshut harabim, a public domain, into a reshut hayachid, a private domain. To convert a “Torah level” reshut harabim into a private domain, a tzurat hapetach, the “form of a doorway,” would not be a sufficient enclosure. This would require solid walls no at least three sides of the area!
A carmelit, however, is an area that does not meet the Torah level requirements for a public domain. The rabbis provided an allowance for a carmelit. It may be enclosed by a tzurat hapetach, literally, the “form of doorway,” or a series of tzurot hapetach, on all sides. By doing so, this area becomes a reshut hayachid, a private domain.
A tzurat hapetach is formed to mimic a doorway: two posts on either side with a connector running over the top. The Talmud describes the construction of such a doorway as follows: kaneh mikan, kaneh mi’kan, v’kaneh al gabeihen, a post on one side, a post on the other side, and post going over the their top.
The posts and top may be made of any material and have no requirements for thickness other than that they remain intact under normal wind conditions (ruach metzuya). The posts must be at least 10 tefachim tall (about 40 inches) and must reach or point directly to the connecting wire on top.
The post on either side of the doorway is known as a lechi.
When a carmelit is surrounded by these “doorways,” the area has now become a reshut hayachid, a private domain.
What we call the “Eruv” is really a misnomer (see below- Eruv Chatzerot). The actual physical construction that makes the confines of the “Eruv” is actually a series of “doorways,” tzurot hapetach.
A tzurat hapetach may be created in a number of ways. For example, we could tie string to run from the top of one pole to another pole. The most common tzurat hapetach used for our “Eruv” is formed by plastic strips that run up the length of a telephone pole. These strips reach a telephone or power cable that functions as the horizontal top for the tzurat hapetach.
In some areas, you will see a string or wire attached connecting the top of light poles. (An example would be on Propspect Avenue)
In certain areas, we are able to utilize an actual wall, a mechitza, such as the fence that runs along the Montclair golf course, from Prospect Avenue until Pleasant Valley Way.
Another type type of mechitza is formed by a natural wall known as a tel. A tel (as in Tel Aviv) is a slope in the earth of approximately 21 degrees (tel hamitlaket araba mitoch eser, rises four amot through the length of ten amot, the dimensions of the ramp going up to the mizbeach.)
An enclosed courtyard that is shared by several families is technically a private domain, a reshut hayachid. However, because this shared space resembles a public domain, the rabbis forbade carrying in this area.
In order to ease this restriction, the rabbis instituted that all of the residents of the courtyard may join together by using an “eruv chatzerot,” literally a “mixing/joining of the courtyard.”
A certain amount of food is placed in one residence and this area must be accessible to all those who reside in the courtyard. In this fashion, the whole courtyard has been made into one single domain, as all the residents have equal access to the food that joins them.
Our Eruv is actually a form of an “Eruv Chatzerot.” After we have constructed the “doorframes,” the tzurot hapetach, that make West Orange into a single domain, we have essentially created a large chatzer, a courtyard, an enclosed area shared by many. It is still forbidden to carry in such a chatzer by rabbinic decree due to its resemblance to a public area.
In order to alleviate this problem, we perform an “eruv chatzerot,” a “mixture” of the chatzerot. It is for this reason that the mechanism by which we are allowed to carry is called an “Eruv.”
We have a Charter from Essex County allowing us to use entire area of the Eruv for the purposes of carrying. In addition, we have several boxes of matza that are placed in a single residence. The matzas are kept in the office of Congregation AABJD. A “new eruv” (i.e. a new set of matzos) is purchased before every Pesach, and the old matza is eaten on Pesach. A beracha is recited when making the new eruv, asher kidshanu b’mitzvotav v’tzivanu al mizvat eruv (see ArtScroll Siddur, page 656)