Ask A Question about the Daf

Previous daf

Eruvin 92

1) HALACHAH: BRIDGES OVER "MECHITZOS"

The Gemara says that a Mechitzah which people walk over ("Darsi Lah Rabim," or a Mechitzah Nidreses) is not considered a Mechitzah.

In many modern metropolitan Eruvin, the wall, or Mechitzah, around the city sometimes passes underneath a bridge over which people travel. What are the laws of a bridge that go over a Mechitzah? May that Mechitzah be used as part of the wall around a city in a modern metropolitan Eruv?

The NODA BI'YEHUDAH (OC 2:42) writes a responsa to someone who asked him about bridges over Mechitzos. The inquirer suggested that the only potential problem is that people walk "through" the Mechitzah by way of the bridge above it and that should be Mevatel the Mechitzah because of the rule of "Asu Rabim u'Mevatli Mechitzasa" (Eruvin 22b). We rule (like Tosfos 22b, see Insights to Eruvin 22) that the presence of people walking through a Mechitzah only invalidates the Mechitzah if it is a natural, and not a manmade wall. Therefore, if the bridge goes over a *man-made* Mechitzah, then the Mechitzah should still be valid.

The Noda bi'Yehudah argues and says that when a bridge goes over a Mechitzah, the Mechitzah is a Mechitzah ha'Nidreses, a trampled Mechitzah, as mentioned in our Sugya. A trampled Mechitzah is different than one through which people walk, and the presence of people trampling over the Mechitzah will invalidate even man-made Mechitzos.

The MISHNAH BERURAH (OC 373:118) rules that if the bridge is more than ten Amos wide, it will effectively make a ten-Amah breach in the Mechitzah below, invalidating the Mechitzah, and a Tzuras ha'Pesach must be built over the bridge to close the breach in the Mechitzah. If the bridge or the road that leads to the bridge crosses straight through from one side of the Reshus ha'Yachid (that is, the enclosed city) to the other side of the Reshus ha'Yachid, i.e. it is "Mefulash," it will not suffice to erect a Tzuras ha'Pesach to close the breach. In such a case the road (or bridge) coming into the city will require doors. (This applies, in fact, to any Reshus ha'Rabim that is Mefulash to -- i.e. pierces through -- a Reshus ha'Yachid, Eruvin 6b).

Therefore, a city that has bridges or roads going straight through it will need doors at the points where the roads enter the city to permit carrying in the city (which is practically impossible to accomplish in today's modern cities).

It is not at all clear, though, what is considered Mefulash

(a) RAV MENACHEM KASHER (Torah Sheleimah 15:172) says that any road that starts at one side of Reshus ha'Yachid and exits at the opposite side, no matter how much it turns and bends in between, is considered Mefulash.

(b) RAV MOSHE FEINSTEIN (Igros Moshe OC 1:140) writes that a street is only considered Mefulash if the road goes straight through the city, without bending at all. (This is obviously a much more lenient ruling, since it is very uncommon to have streets that "pierce" through cities.).

92b

QUESTION: The Gemara says that when there are grapevines in the small Chatzer, it is permitted to plant wheat in the large Chatzer adjacent to it. As far as the larger one is concerned, it has Mechitzos and is separate from the smaller Chatzer and there is no problem of Kil'ayim.

However, the smaller Chatzer does not have Mechitzos. Since it does not have Mechitzos, when the wheat is planted in the large Chatzer, the grapevines in the smaller one should become forbidden! If so, how can it be permitted to plant wheat in the larger Chatzer if doing so will make the grapevines in the smaller Chatzer forbidden as Kil'ayim?

ANSWERS:

(a) RASHI says that the Gemara is not talking about Kil'ei Kerem (mixtures of grapevines and wheat). Rather, the Gemara is referring to mixtures of other plants (Kil'ed Zera'im), such as vines and beans, which are only forbidden mid'Rabanan. The Rabanan forbid such mixtures post facto only as a penalty for planting in a manner forbidden by the Rabanan. When one plants different species of plant together in a permissible way, such as by planting one in the large Chatzer *after* having planted the other in the small one, the produce of both plants is permitted. The Rabanan saw no reason to penalize him in such a case. Therefore, even the plants in the smaller Chatzer remain permitted.

(b) TOSFOS says that when there is a large and small Chatzer, not only are the contents of the small Chatzer considered to be "together" with the contents of the large one, but the classification that is given to the large Chatzer is given to the small Chatzer as well.

The Torah forbids planting wheat in a "Kerem," a vineyard -- "You shall not plant Kil'ayim in your Kerem." That is, the prohibition has nothing to do with whether there actually are grapes there or not (in fact, in our case there are *no* grapes within 4 Amos of the smaller Chatzer, and the fruit themselves are not mixed), but rather with the fact that the area is defined as a "Kerem." For this reason, when there are vines in the larger Chatzer, making it a "Kerem," the smaller Chatzer becomes a "Kerem as well and may not be planted with wheat. On the other hand, if there are grapevines in the smaller Chatzer, the larger one is not designated a "Kerem," since it is not affected at all by what is planted in the smaller one. Therefore, it may be planted with wheat. (Although this will make the smaller one takes on the name of a "Sadeh," or wheat-field, we do not find that it is prohibited to plant grapes in a Sadeh; it is only forbidden to plant *wheat* in a *Kerem*).