Defining Reshus HaRabbim D' Orayssa

[Note: This piece continues the theme of the last post regarding eruvin. For more on this topic see the article by R' Hershel Schachter in The Journal of Halacha and Contemporary Society. Many of the ideas in this piece are lifted from that article.]

In order to be defined as a Reshus HaRabbim D’Orayssa there are conditions that must be met. The more conditions that there are, the harder it will be for us to declare an area as a reshus harabbim d’orayssa and the easier it will be for us to build an eruv in that area. The following is a list of conditions needed to declare an area a reshus harabbim d’orayssa. Some of the conditions are subject to dispute:

1. The area should be owned by the public (Eruvin 59a). For example, even if Rockefeller Center met all the criteria of being a reshus harabbim it still would not be one because it is not public owned.

2. The area should not have a ceiling (OC 345:7).

3. The streets should be more than 16 amos wide (OC 345:7).

4. The area should be accessible at all times (Eruvin 6b).

5. The area should have 600,000 people traversing it. This condition is a dispute between rishonim (see Eruvin 59a). It has generally been assumed for generations that we follow the lenient opinion of Rashi and Tosafos that we require the 600,000 in order to declare an area a Reshus HaRabbim. However, some acharonim (see Mishkanos Yaakov OC 120) question this and prefer to follow the Rambam. They contend that the majority of rishonim are actually on the Rambam's side. The acharonim also argue about how exactly to calculate the 600,000.

6. The street should be mefulash through the entire city. This means it runs straight through the city from end to end. R' Shlomo Kahana reportedly (quoted by R' Kasher in Noam) used this leniency to allow the eruv in Warsaw to remain valid. He argued that there was no street that ran straight through the city from end to end with no curves. R' Moshe Feinstein (OC 140) questions the legitimacy of this leniency.

Here are some factors to consider l'chumra when trying to make an eruv:

1. We hold in general that all highways (derachim me’ir l’ir - see Magen Avraham 345:5) are automatic reshuyos harabbim. This means that even if the highway doesn't fulfill all the conditions, the very fact that it is a highway makes it a reshus harabbim.

2. Rav Moshe (Volume 1 of Iggros Moshe, page 240) makes an argument that all central metropolis areas are automatic reshuyos harabbim. The argument is based on a Rabbeinu Efraim that (based on R' Moshe's understanding) says that Yerushalayim did not have an eruv even though it wasn't a reshus harabbim according to the conditions set out above (because it's doors were locked at night). Why not? Because it was the central Metropolis of the area, where everyone gathered. Based on this R' Moshe argues that Manhattan cannot have an eruv.

Here are some additonal factors l’kula:

Aruch HaShulchan (OC 345:19-24) – In order to be a reshus harabbim the street must be the main street of the city. Nowadays all streets cancel each other out and there is no main street. (See Divrei Malkiel Vol. 3 page 267 where R' Tannenbaum opposes using this leniency.)

Chazon Ish (Hilchos Eruvin Siman 43, see especially Os 7. See also Orchos Chaim Vol. 1 page 139 who quotes earlier poskim who agree with the Chazon Ish.) – Nowadays our buildings and houses actually enclose the streets enough to render the entire city into a reshus hayachid. The Chazon Ish demonstates this with diagrams of how our cities are generally constructed. He also relies on some ideas that others question (see Or HaMizrach Nissan 5741).