ERUVIN 22 - dedicated by Rabbi Kornfeld's father in memory of his aunt, Malka Gitel bas Reb Yakov Mordechai (Malvina Marmorstein), who took him into her home and raised him like her own child after the Holocaust. Her Yahrzeit is 20 Nisan.

QUESTION: Rava explains that we learn from the verse, "Shechoros ka'Orev" (Shir ha'Shirim 5:11) that Torah scholarship is to be found in one who is unkind towards his children (because he knows that Hash-m will look after them) like a raven (who forsakes its offspring, leaving them in the hands of Hash-m).
The Gemara says that this is like the practice of Rav Ada bar Masna. When Rav Ada bar Masna left his family to go learn in Yeshiva, his wife asked what their children would eat while he was away learning. He replied, "Are the vegetables (or reed-grasses) in the marshes all gone?"
It seems that Rava is praising a person who studies at the expense of providing support for his children. How can such a person be considered praiseworthy? The Gemara in Kesuvos (49b) clearly requires a father to support his young children!
ANSWER: The Gemara in Gitin (6b) condemns those who neglect the support of their family in order to go study Torah. (This is the understanding of Tosfos there (DH v'Yitnu) and in Kidushin (29b, DH Ha Lehu). According to Rashi in Kidushin, it seems that this was the subject of a dispute between the sages of Eretz Yisrael and the sages of Bavel. However, even according to Rashi, the sages of Bavel maintained that one may leave his home to go learn before he has children, and only with the permission of his new wife, but not after he has children to support.)
Rava does not praise a person who does not provide support at all for his family. Rather, Rava praises a person who does support his family by providing their essential needs even while he is away learning Torah. The Gemara refers to this basic amount of support when it says that Rav Ada bar Masna provided his family with the wild vegetables of the marshes.
Rava means that the study of Torah overrides the responsibility to provide more than the basic amount of support (as we find, for example, later in Eruvin (end of 55b; see Rashi there, DH Ein Talmid Chacham)). Rava says that a person who wants to become a Talmid Chacham should not leave his studies in order to provide a life of luxury for his family. (M. KORNFELD)


QUESTION: The Gemara asks that if the cliffs of Tzur and the banks of Gader are considered Mechitzos enclosing Eretz Yisrael, then Bavel should also be considered a Reshus ha'Yachid because of the Tigris and Euphrates Rivers that surround it. The Gemara concludes that Eretz Yisrael and Bavel are certainly not considered Reshuyos ha'Yachid as a result of the natural partitions around them, because if natural partitions make a country into a Reshus ha'Yachid, then the entire world should be considered a Reshus ha'Yachid, since every land mass is surrounded by natural Mechitzos (such as the sea).
Why are entire countries indeed not considered Reshuyos ha'Yachid? The cliffs and other natural partitions around them should make them Reshuyos ha'Yachid! (TOSFOS DH Dilma)
According to the view of Rebbi Yehudah, this is not a question. Rebbi Yehudah maintains "Asi Rabim u'Mevatel Mechitzah" -- the public traffic that travels through the area of the natural partitions nullifies the Mechitzos. However, we rule in accordance with the Rabanan who maintain that public traffic does not invalidate Mechitzos. According to the Rabanan, why do natural partitions not serve as Mechitzos to make Eretz Yisrael and Bavel Reshuyos ha'Yachid? (Even though the cliffs were not originally created for the sake of serving as Mechitzos around residential areas, the law mid'Oraisa is that even a Karpaf larger than Beis Se'asayim that was not Hukaf l'Dirah is a Reshus ha'Yachid!)
(a) TOSFOS (DH Dilma) answers that even the Rabanan agree that public traffic can invalidate Mechitzos if those Mechitzos were not man-made but were made by Hash-m. Only man-made Mechitzos are not invalidated by people walking through them. Mechitzos made by Hash-m are not considered Mechitzos if people walk through them.
(b) The RITVA and RASHBA explain that if an area is so large that when one stands in the middle of the area he cannot see the partitions that surround it, those partitions cannot make it a Reshus ha'Yachid (see also SHA'AR HA'TZIYUN OC 363:94).
(c) The RAMBAN also writes that the area enclosed by Mechitzos that are very far apart is not considered a Reshus ha'Yachid. However, the MISHNAH BERURAH (345:48, and in Bi'ur Halachah 346:3) points out that the Ramban says this only with regard to Mechitzos that were made by Hash-m and are so distant that they cannot be seen from the middle of the enclosed area.
QUESTION: The Gemara says that Shevilei Beis Gilgul, the winding path that goes up a mountain, is considered a Reshus ha'Yachid if it is so steep that a servant cannot carry a bundle of wheat and run with it in front of his master.
Why is it necessary that the path be difficult to climb in order for it to be considered a Reshus ha'Yachid? Since the mountain itself rises more than ten Tefachim within a distance of four Amos, the sides of the mountain should be considered Mechitzos and the top of the mountain should be considered a Reshus ha'Yachid, even if the path winds so much that it is not steep and thus not difficult to traverse! (Even though there is public traffic along the path, the Rabanan maintain that public traffic does not invalidate Mechitzos.) Why does it depend on whether a servant can run up with a bundle of wheat?
(a) The TOSFOS HA'ROSH answers that according to the Gemara's conclusion, even Rebbi Yehudah (who normally maintains that public traffic invalidates the effectiveness of Mechitzos) agrees that such a hilly area is a Reshus ha'Yachid even when many people walk through it. At the time that Eretz Yisrael was divided among the people, Yehoshua gave all of the hilly areas of Eretz Yisrael to individuals, and property owned by individuals cannot become a Reshus ha'Rabim.
The Tosfos ha'Rosh explains that Yehoshua gave to individuals only the areas that are extremely hilly, which a person would not be able to ascend without becoming exhausted. Accordingly, the Beraisa stipulates that only an area which a servant can ascend while carrying a bundle is considered a Reshus ha'Rabim. If he cannot run up with ease, then that indicates that the area was given to an individual. An area that is not so steep was given to the public (and the presence of public traffic invalidates any Mechitzos that might be there, making it a Reshus ha'Rabim despite its Mechitzos).
However, this explains the Beraisa only if it follows the opinion of Rebbi Yehudah. Why did the Gemara first assume that the Beraisa follows the opinion of the Rabanan?
(b) TOSFOS (DH v'Eizehu) explains as follows. The Gemara later (89b) teaches the Halachah of a "Mechitzah Nidreses." Normally, Mechitzos ten Tefachim high are viewed to continue upward until the sky (due to the principle of Gud Asik) and the entire area above those Mechitzos is a Reshus ha'Yachid. However, when people step over a Mechitzah, the presence of those people prevents Gud Asik from functioning.
Even though the mountain of Beis Gilgul is considered a Reshus ha'Yachid due to the Mechitzos all around it (that is, the sides of the mountain reach a height of ten Tefachim within four Amos, and therefore the sides are considered Mechitzos), in order for the area on top of the mountain to be considered a Reshus ha'Yachid we must apply Gud Asik (in order to view the sides of the mountain as though they extend upwards above the level of the mountaintop and enclose that area). If there is public traffic atop the sides of the mountain that serve as the Mechitzos, then Gud Asik cannot work. Accordingly, Tosfos says that if it is not such a steep hill and the public can climb it easily, it is not considered a Reshus ha'Yachid because its Mechitzos are "trampled." It is considered as if it does not have Mechitzos at the top of the mountain. If, however, the mountainsides are very steep and not easily traversed, then the Mechitzos are not trampled and they remain intact. Gud Asik makes the Mechitzos rise to the sky and enclose the top of the mountain, making it a Reshus ha'Yachid.