Part 1: Why Brooklyn Is Not a Reshus HaRabbim

Since the streets of our community do not run straight from one end of the city to the other ― they are not mefulashim u’mechuvanim m’shaar l’shaar.

Most poskim use the term mefulash m’shaar l’shaar without differentiating between a walled city and an open city (see also Mefulash According to the Shulchan Aruch). Since this is a very important distinction and has a great impact in how we apply the criterion of mefulash, we can garner from this omission that there is no difference halachically whether or not the city is walled.

The following is a partial list of poskim who are clearly not referring to a walled city:

• The Mishnah Berurah (364:8), when describing the cities of his times, stated that there were streets that were sixteen amos wide and mefulash m’shaar l’shaar. Therefore, a Baal Nefesh should be stringent since to erect an eruv in these cities they had to rely on the fact that the street did not have shishim ribo traversing it. As we know that most towns in his times were not walled ― even in earlier times most cities were not walled, Pri Megadim (Mishbetzes Zahav 362:17) ― we can deduce that he accepted the criterion of mefulash as not being dependent on a walled city.
• The Divrei Malkiel (4:3) states that to find a street in a large city which is mefulash, open from one end of the city to the other, is unheard of and that is why the minhag is to erect eruvin even in the largest of cities. He wrote this teshuvah regarding Odessa, a city that was not walled.
• Rav Shlomo Dovid Kahane zt”l (Divrei Menachem, O.C. vol. 2, pp. 42-43), one of the main rabbanim of Warsaw before World War II, posited that the heter to erect an eruv in a large city such as Warsaw, which was not walled from the year 1877 (Encyklopedia Warszawy, 1994 p. 187), was universally accepted as the streets were not mefulashim u’mechuvanim m’shaar l’shaar. More so, he claimed, a small city would have a greater problem establishing an eruv since its streets would be mefulash. In a small city there is usually one main street running straight through the center of the town as opposed to a large city where the streets are generally not straight from city gate to city gate.

It is important to note that Rav Moshe zt”l (Igros Moshe, O.C. 5:28:7) disagreed with the above poskim and maintained mefulashim u’mechuvanim m’shaar l’shaar is a criterion that can only be utilized in a walled city. However, since we have established that Brooklyn is a walled city ― because it is circumscribed on three sides by mechitzos ― Rav Moshe would agree that our streets have to be mefulashim u’mechuvanim m’shaar l’shaar in order to be classified as a reshus harabbim.

Mefulash According to Most Poskim

Most poskim understand mefulash m’shaar l’shaar as meaning mefulashim u’mechuvanim m’shaar l’shaar, open and running straight from city gate to city gate (Bais Yosef, 345:8; Magen Avraham, 345:6; Pri Megadim, Aishel Avraham, 364: 2; Bais Ephraim, O.C. 26; Tiferes Yisroel, introduction to Shabbos; U’Bacharta B’Chaim, siman 123; Shoel U’Maishiv, 2:87; Yehudah Yaleh, O.C. siman 54; Mahari Slutsk, O.C. siman 11; Minchas Elazar, 3:4, and Mishnah Berurah, 345:20). Rav Aharon Kotler zt”l states (Mishnas Rav Aharon, 6:2), that for a street to be classified as a reshus harabbim it is accepted that it would have to be mefulashim u’mechuvanim m’shaar l’shaar ― although he personally maintains that it is dependent on a walled city.

Mefulash According to the Shulchan Aruch

The text of the Shulchan Aruch reads:
“What is a reshus harabbim? A street or marketplace that … is not walled and even if they are walled but they [the street or marketplace] are open from city gate to city gate, they [the street or marketplace] would be considered a reshus harabbim ….”

Even though the Shulchan Aruch cites the criterion of mefulash m’shaar l’shaar in conjunction with a walled city, the Tur does not differentiate between a walled city and an open city and the Bais Yosef (siman 345) does not disagree with the Tur. Therefore, mefulash would be considered a criterion of a reshus harabbim even in a city that is not walled (see Bais Av, 2:9:1 for a detailed explanation). The Gra offers a different perspective (Bi’ur HaGra, O.C. 345:7) and explains that the words of the Shulchan Aruch, “is not walled,” refers to a street [sratya]. The Dmesek Eliezer clarifies the Gra that a sratya is a road which does not have a wall around it. The Gra explains further that, “even if they are walled,” refers to a marketplace [platya]. The Dmesek Eliezer explains that a platya is a city street that is walled on two sides and the remaining two sides are open straight from city gate to city gate. What we see from this Dmesek Eliezer is that what the Shulchan Aruch refers to as, “walled,” pertains to the streets of the city and not the city walls. Therefore, it is understandable why the Gra (Sh’nos Eliyahu, introduction to Meseches Shabbos and Chidushi HaGra, Shabbos 6a) when discussing the criterion of mefulash m’shaar l’shaar does not attribute it to a walled city. It follows that our streets which are lined with houses would be classified as walled streets and would have to be mefulashim u’mechuvanim m’shaar l’shaar to be categorized as a reshus harabbim. Note that since the term city gate [shaar] does not always pertain to the gate of a walled city (Rashi, Yoma 11a), mefulash m’shaar l’shaar can refer to a city that is not walled as well.