QUESTION: The Gemara relates an incident in which a two-story house began to sink into the ground. The owner of the ground floor demanded that the owner of the upper floor help him rebuild the house, and the owner of the upper floor refused. Rav Chama ruled that the owner of the upper floor was not required to help the owner of the lower floor restore his dwelling, nor was he required to move to a different house -- even at the expense of the owner of the lower floor -- in order to let the owner of the lower floor repair his dwelling at his own expense. However, if the house had sunk into the ground so much that the upper floor was within ten Tefachim of the ground, the owner of the lower floor would be able to force his upstairs neighbor to help him restore the house, since those ten Tefachim are the exclusive domain of the owner of the lower floor. The ROSH explains that in such a case the owner of the lower floor can force the upstairs neighbor to help him demolish the structure and rebuild it anew (before it sinks entirely into the ground).

Even though ten Tefachim is the minimum height necessary for living space (as the Gemara says in Sukah 3a), why does the owner of the lower floor have no recourse until he no longer has ten Tefachim? If he originally had, for example, twenty Tefachim of height for his living space, all of that space should be his exclusive domain. Once the upper floor enters the space within twenty Tefachim, the downstairs neighbor should be able to force the upstairs neighbor to help restore the house. Indeed, when the house is demolished and then rebuilt, the downstairs neighbor is entitled to rebuild his home at its original height. This indicates that the entire space that the lower floor originally occupied does belong to the downstairs neighbor. Why, then, can he not force the upstairs neighbor to help him rebuild the house as soon as the upper floor begins to sink? (ME'IRI, KOVETZ SHI'URIM)

The Me'iri rejects this answer because the Gemara gives no indication that any condition of that sort was made.

QUESTION: The Gemara relates an incident in which two brothers (Reuven and Shimon) divided property that they inherited. Reuven took a hall, and Shimon took the garden next to the hall. Shimon began to build a wall between the garden and the hall. Reuven complained that the wall would block his light, while Shimon claimed that he was entitled to build the wall because it was on his own property. Rav Chama ruled that Shimon was entitled to build the wall.

The Gemara asks that even if Reuven had compensated Shimon only for the value of the stones and building materials that he received, and not for the right to have his hall open to air and light, Reuven still should have been able to claim that he initially accepted the hall with the understanding that it would be useful and have light, and now he will have only a dark room.

Rav Simi bar Ashi answers that even a darkened hall is still called a hall, and thus Reuven will have the same thing that he initially received. The Gemara cites a Beraisa to support this assertion. The Beraisa says that if a person sells an "orchard" to a purchaser and it turns out that there are no fruits growing in the orchard, the sale is binding when such a field is called an "orchard."

The RASHBA asks that the Beraisa does not support Rav Simi bar Ashi's answer. In the case of the Beraisa, the seller initially sold the orchard without any fruit in it. In contrast, in the Gemara's case Reuven initially received a hall with light, and only afterwards did Shimon take that light away by building a wall. The Rashba argues that this is comparable to a case in which a person sells an orchard with fruit and then goes and picks all of the fruit. In such a case, the fruit certainly belongs to the buyer, even if a field without fruit is also called an orchard. Here, too, Reuven acquired the right to have light in his hall, and Shimon should not be permitted to take it way from him. How, then, does the Gemara support Rav Simi bar Ashi's answer from the Beraisa?

ANSWER: The RASHBA answers that the comparison to the case of the Beraisa is accurate. In the case of the brothers who inherited a hall and a garden, Shimon, the brother who received the garden, did not actively take away light that Reuven had already received. Rather, he indirectly caused the light not to reach the hall. Hence, the hall was effectively the same hall that Reuven received initially.

The KOVETZ SHI'URIM adds that this explanation of the Rashba answers the question of TOSFOS on RASHI here. Rashi (DH bed'Nafsha'i) writes that Shimon, the owner of the garden, was permitted to build his wall because Reuven, the owner of the hall, did not have a Chazakah of three years to have light in his hall. Tosfos asks how this could be a reason to permit Shimon to completely darken Reuven's hall. The Kovetz Shi'urim explains that Tosfos' question is that the brother who built the wall actively damaged ("Mazik b'Yadayim") the other brother's property by blocking the light, even though he built the wall on his own property.

Rashi, in contrast, agrees with the view of the Rashba who explains that blocking light is not considered "Mazik," but rather is an indirect result of building a wall. Therefore, the owner of the garden was allowed to build the wall as long as the owner of the hall had not established a Chazakah that entitled him to have his wall exposed to the light. (I. Alsheich)

QUESTION: The Gemara relates that a certain Chasid built a Beis Sha'ar, an outer gatehouse, outside of his courtyard (which prevented people from entering his courtyard). The Beis Sha'ar prevented poor people from entering the courtyard to collect charity. As a result, Eliyahu ha'Navi stopped speaking to the Chasid.

Why does the Gemara need to point out that Eliyahu stopped speaking to the Chasid? The Gemara could have said simply that it is not proper to build a Beis Sha'ar which prevents poor people from entering.