If Shimon initially agreed to rebuild the house should the lower floor sink into the ground, the Tana informs us, then he must comply with that condition (see Chidushei Anshei Sheim). To determine how far the ceiling may sink before the house is considered uninhabitable, we cite Mar Zutra quoting his father, Rav Nachman - who gives the minimum height of a ceiling as the length plus the breadth divided by two.

He learned this from the Heichal (of the Beis-Hamikdash), which was forty Amos long, twenty Amos wide and thirty Amos tall.

When they quoted Rabah (or Rava) Mar Zutra's statement - he scolded them for misrepresenting Rav Nachman.

According to him, for an apartment to become uninhabitable, the ceiling may sink up to the point - that the owner can enter his house in the normal manner, meaning with a bundle of long canes on his shoulders, and is still able to turn round in all directions without bumping into a low beam, as Rav Huna b'rei de'Rav Yehoshua puts it.

When, due to the fact that Reuven's wall prevented light from entering Shimon's windows, Shimon ...

... complained, Reuven offered to seal his windows and build new ones at a point that was higher than his wall.

... declined his offer, because building new windows into an old wall tends to weaken it - he offered to break down the top part of the wall of Shimon's house, as far as his wall, and to rebuild it with windows at a point higher than his own wall.

... declined that offer too, on the grounds that a wall that is half old and half new, will not last - he offered to demolish the entire wall and rebuild it, again with windows higher than his wall.

... insisted that this too, was no good, since one new wall in an old house will not last either - he offered to demolish the entire house and rebuild it, once again with the windows higher than his own wall.

The basis of Shimon's last two claims was - that new cement and old cement do not bind well together.

When Shimon even declined to have Reuven rebuild his house from scratch, because he had nowhere to live in the interim - he offered to rent him a house.

Here too, like in the previous case, Rav Chama ruled that Shimon had acted within his rights in declining to accept all of Reuven's offers. Despite the similarity between the two cases, we need to cite the second one - which speaks when Shimon was using the house (not as a residence but) as a storehouse for straw and wood. And this teaches us that a neighbor is entitled to be fussy about the conditions under which his goods are being stored, no less than he is about the conditions under which he resides.

The Gemara cites a case where Reuven chose the banqueting hall that his deceased father had left behind, and Shimon his brother, the garden in front of it. When Reuven complained that the wall that Shimon built in his garden, darkened his palace the latter replied - that he had built it in his own domain (and there was nothing that Reuven could do about it).

Here too, Rav Chama substantiated Shimon's claim. Ravina queried him from a Beraisa, where the Tana rules that if one of two brothers takes the vineyard that his deceased father left behind, and the other, the wheat-field - the former is entitled to the four Amos that are required to work the vineyard, since it is on that condition that they divided it.

Rav Ashi reconciles Rav Chama with this Beraisa by establishing the latter - where they came to terms over the fact that a vineyard is worth much more than a corn-field, and the latter therefore had to pay the former for this advantage, including the four Amos of Avodas ha'Kerem. Whereas the case of Rav Chama speaks where they did not come to terms, allowing the owner of the garden to do whatever he saw fit in his garden.

When Ravina asked Rav Ashi further whether the brother who chose the garden rather than the banqueting hall without coming to terms, was not crazy, he replied - that they had certainly come to terms over the value of the bricks and beams, but not over the air of the living-space.

The brother who chose the banqueting-hall cannot claim that he picked the banqueting-hall, which, due to the current darkness, was now reduced to an ordinary room - because the banqueting-hall remained a banqueting-hall in name, even though it was no longer as posh as it originally had been.

Rav Shimi bar Ashi bases this on a Beraisa, which rules in the case of 'ha'Omer Beis-Kur Afar Ani Mocher lach, Af-al-Pi she'Eino Ela Lesech' (or 'Pardes O Kerem Ani Mocher lach, Af-al-Pi she'Ein bo Rimonim O Gefanim'), Higi'o (It's too bad)'. A Lesech is - half a Kur (i.e. fifteen Sa'ah).

The reason behind the Tana's ruling is - because he only meant to sell him something that was called 'a Beis-Kur', 'a Pardes' and 'a Kerem' respectively, provided that they really were called by that name.

Ravina rejects this comparison however, on the grounds - that one can sell an article on whichever condition one pleases, but a son who picks an article from his father's inheritance, expects to use it in the same way as his father did.

Mar Yenuka and Mar Keshisha - sons of Rav Chisda, answered Ravina's Kashya by stating 'Neherda'i le'Ta'amaihu, de'Amar Rav Nachman Amar Shmuel ... '.

The connection between the Neherda'i and ...

... Rav Nachman Amar Shmuel is - that they were both from Neherda'a, and so was ...

... Rav Chama.

Rav Nachman Amar Shmuel ruled that brothers who divided their father's inheritance - do not have the right to a path through their brother's fields to get to their own, nor any claims to build windows to create more light, nor the right to place ladders in their brother's Chatzer to get to their attics.

This vindicates Rav Chama - because we now see that the Neherda'i do not require the son to use the property in the same way as their father did.

Rava disagrees with the Neherda'i. He holds - that each brother is entitled to all the rights that their father had.

In a case where Yesomim produced a Sh'tar against the debtor, who, in turn, produced a receipt, Rav Chama ruled - that we neither accept their claim (because of the receipt), nor do we tear up the Sh'tar-Chov (in case the Yesomim succeed in invalidating the receipt when they grow up).

Ravina told Rav Acha b'rei de'Rava that, whereas in all the previous cases, the Halachah was like Rav Chama, in this case it was not - because there were no grounds to query the Chezkas Kashrus of the witnesses on the receipt.

Mar Zutra b'rei de'Rav Mari disagrees with Ravina - because the debtor ought to have produced the receipt during the lifetime of the father (assuming that he too, claimed from the debtor [Ritva]). Since he did not, it seems that the receipt is forged.

The Tana Kama of our Mishnah obligates every member of the Chatzer to pay towards the costs of building a Beis Sha'ar (an out-house) and a door (as we have already discussed). Raban Shimon ben Gamliel maintains - that not all courtyards require a Beis-Sha'ar.

The three things that the Tana Kama obligates all residents in a town to share the costs are - a wall, doors and a bolt.

In order to be considered a member of the town in this regard - one needs to have lived there for twelve months.

One is considered a member immediately however - upon purchasing a house in the town.

Eliyahu ceased communicating with a certain Chasid with whom he had previously communicated regularly - because he built a Beis-Sha'ar to his Chatzer, thereby preventing the poor from obtaining help when they called from outside the locked door and nobody would hear them.

We reconcile this episode with our Mishnah in a number of ways. Initially, howwever we draw a distinction between whether the Beis-Sha'ar is inside the Chatzer (the episode with Eliyahu) or outside in the street (our Mishnah) ...

... inasmuch as, the former is normally locked, denying the poor access, whereas the latter generally has no door, allowing the poor easy access to the Chatzer.

The episode with Eliyahu could be speaking even if the Beis-Sha'ar was on the outside, assuming that it has a door and a lock. On the other hand, we might even establish our Mishnah where it has ...

... a door - but no lock, or ...

... a lock - but which is on the outside of the door, with the key fitted inside.

When Raban Shimon ben Gamliel says that ...

... not all Chatzeros require a Beis-Sha'ar - he is referring to courtyards that do not open on to a main street.

... not all towns require doors - he is referring to those that are not near the border.

The Rabbanan counter that ...

... all courtyards require a Beis-Sha'ar - because sometimes there is an overflow from the nearest main road, even though the Chatzer itself does not open directly on to it.

... all towns require doors - because sometimes the enemy attacks even towns that are not on the border.

Rebbi Elazar asked Rebbi Yochanan whether the residents of the town must pay per capita or according to their means. In fact, Rebbi Yochanan holds - that they pay according to their proximity to the wall.

His concluding words on the matter are - 've'Elazar B'ni, K'va bo Mismoros' (meaning that Rebbi Elazar should fix this ruling in his mind and not waver from it).

In the second Lashon, Rebbi Yochanan gave Resh Lakish the same reply, though the She'eilah there was - whether they pay according to their proximity to the wall or according to their means.

When Rebbi Yehudah Nesi'a (Rebbi's grandson) asked the Chachamim to pay towards the costs of building the city-walls - Resh Lakish informed him that the Chachamim do not require guarding and are therefore not subject to this tax (as we learned in Bava Metzi'a).

The Pasuk "Asaprem me'Chol Yirbun" ('I will count them, and they are more numerous than the sand') cannot refer to the Tzadikim - because we have learned in a Pasuk in Vayeira that the whole of Yisrael are only as numerous as the sand on the seashore (so how can the Tzadikim alone be more than that).

Consequently - it must be referring to their good deeds.

Resh Lakish now extrapolates from the sand - that if the sand which is numerous, protects the sea-shore, then the good deeds of the Tzadikim, which are more numerous still, should certainly protect the Tzadikim.

Rebbi Yochanan asked Resh Lakish why he did not quote Rebbi Elazar the Pasuk "Ani Chomah, ve'Shadai ka'Migdalos". Rebbi Yochanan explained ...

... "Ani Chomah" - 'Zu Torah!'

... "ve'Shadai ka'Migdalos - 'Eilu Talmidei-Chachamim' (who sustain Yisrael with their merits, like a woman's breasts sustain her babies).

Resh Lakish explains the Pasuk like Rava, according to whom ...

... "Ani Chomah" refers to - 'K'neses Yisrael'.

... "ve'Shadai ka'Migdalos" - to the Shuls and the Batei Medrash.