Explanation #1 (Rashi): [This means] bend your stature.

Explanation #2 (Ri): "Shuf" is an expression of rubbing. He [goes on his stomach] and scrapes the ground.

Explanation: The Targum of "Anashim Rekim" (empty people) is Guvrin Serikin.

Question: This episode teaches that a new wall will not stand well on an old wall. We do not learn this from the above episode [of the house that sank];

We need the above episode like we say, that this is only if the beams [of the upper story] do not descend within 10 [Tefachim of the ground! Why does the Gemara ask why both were taught?]

Answer: It is obvious that [a new wall on an old wall, or] one new wall and three old walls do not stand. Due to this, there was no need to bring this episode.

Explanation #1 (Rashi): This is a nice hall.

Explanation #2 (Aruch): This is a cave, like the Targum of "Mipnei Sha'ul ba'Me'arah" is b'Asplida.

Rebuttal #1 (Ri): Here, Asplida cannot be a cave, for it says that they compensated for the bricks and beams of the Asplida. A cave does not have bricks and beams!

Rebuttal #2: [The Gemara] says "initially it was an Asplida, and now it is Idruna (a dark room). A cave does not have light at all!

Explanation #3 (Ri): Here, Asplida is an Achsadra (a building without four walls). It has much light, like we say below (25a) that the world resembles an Achsadra.

Support: So it is proven in Menachos (33b). Abaye said "I saw the Asplidi of [Rabah's] house. They have pillars, but they do not have Mezuzos;

We challenge this, for a gate house, Achsadra and porch are obligated in Mezuzah.

Explanation #1 (Rashi): [He tells him] you do not have a Chazakah against me for three years to have light.

Question #1: It is astounding that he can darken for him, and his [Achsadra] will not have light at all!

Question #2: Why does it say "they did not compensate each other for air"? Surely they compensated for air, for a house without light is not worth anything!

Explanation #2 (R. Tam): From the Asplida he was able to see to his fields through the garden. He said "you darken for me", i.e. he prevents him from seeing his fields;

He calls it "a dark room" because he cannot see far. He explains similarly the case below "they do not have windows against each other.

Question (Ri): What was the question "why is this unlike the Beraisa?" There, surely he has four Amos, for they are needed to work the vineyard;

However, here [seeing the fields] was not a need of the Asplida. Therefore, he properly told him [I build in my own].

Explanation #3 (Ri): Surely, he darkened for him its light. It did not have as much light as an Achsadra needs, but it still had much light;

It says "opposite [windows] he distances four Amos so he will not darken", i.e. he will not darken totally to the point that it cannot be used well. This is why he calls it a dark room, for compared to an Achsadra, it is a dark room.

Support: This is fine that they did not compensate for air, which is needed for an Achsadra.

Explanation: The case is, the buyer knows that he has land that is called a Beis Kor. If not, he tricked him!

Even if [the buyer] sees it at the time of the sale, that it is not a Beis Kor, he can say "I thought that you would complete for me a Beis Kor."

Question: He should say that the money proves [how much he bought]. If he paid the price of a Beis Kor, even if it is called "Beis Kor", he should complete for him a full Beis Kor!

Answer #1: The case is, he sold to him cheaply, and he does not pay even for half a Beis Kor. If they call it a Beis Kor, even if it is only half a Beis Kor, the sale stands.

If it is not called "Beis Kor", he must give to him a full Beis Kor.

Answer #2: He did not sell to him cheaply. The case is, he gave to him the money for half a Beis Kor. If it were not called a Beis Kor, the buyer could say "if you want to give to me a full Beis Kor and fulfill your sale, do so. If not, return to me my money;

However, if they called it a Beis Kor, the sale stands, even though it is only half a Beis Kor.

Explanation: He is the older [brother]. Because he was born in Rav Chisda's youth, he is called Mar Yenuka;

Mar Kashisha is the younger [brother]. He was born in Rav Chisda's old age (see Rashi Kesuvos 89b DH Mar, who explains that Mar Yenuka was the younger one).

Explanation: R. Chama was from Neharde'a, like we say in Sanhedrin (17b) "the Amora'im of Neharde'a" refers to R. Chama;

Also Shmuel was from Neharde'a, like Shmuel said (Brachos 58b) "I know the paths [of the stars in the sky] like the paths of Neharde'a."

Explanation: This is because Shmuel ruled below (64a) like R. Akiva, who says that people sell generously, therefore they do not have [rights to] a path against each other;

Each did not leave for himself a portion in his friend's portion. He is like a seller.

Implied question: We say that one who sold a house and left [for himself] the Chatzer, he sold to him with the path [to the house], according to the opinion that people sell generously!

Answer: There is different. Here, they all sell. Everyone sold and did not leave for himself anything in his friend's portion;

He is like one who sold a Chatzer and left [for himself] the house. He must buy a path from the [new] owner of the Chatzer.

Explanation #1 (Rashi): If this one received a house and Chatzer, and this one received an Aliyah, he may not fix a ladder in the other's Chatzer to ascend to his Aliyah.

Question (Ri): This is the same as not having a path in each other's property! (Why did the Mishnah need to teach also this?)

Explanation #2 (Ri): The case is, this one received a house, and this one received a Chatzer and an Aliyah. He may not fix a ladder near the other's wall [of his house] to ascend to his Aliyah.

Assertion: The text does not say "both of these are from the inside", for if it is inside, we cannot distinguish between whether or not it has a door, or whether or not it has a key;

In any case it is bad, since [the Oni] can come only until the opening of the Chatzer.

Suggestion: "This is when it has a door" refers to the Chatzer!

Rejection: Our Mishnah explicitly teaches that they can force each other to build a door for the Chatzer. (Presumably, every Chatzer has a door.)

Question: The text "[both of these are] from the outside" is slightly difficult, for it is unlike the other answers, in which we discuss the bad way - "in both cases it has a door", and "in both cases it has a key", and here it mentions the good way!

Explanation: Since there is no mortal danger, we go only according to money (everyone pays proportionate to his wealth).

Support: We say so in Bava Kama (116b). If a caravan was going in the Midbar, and a troop came against it, we calculate [how much everyone must pay towards the bribe given to placate them] according to money, since the troop comes only for money.

Question: It says in Sanhedrin (72a) that one who tunnels under a house [in order to steal] is judged based on his end;

Rava explains that there is a Chazakah [of human nature] that one does not restrain himself when someone takes his money. [The thief anticipates that the Ba'al ha'Bayis will oppose him, and he plans to kill the Ba'al ha'Bayis. We should say the same about the troop!]

Answer: Even so, we calculate only according to money, since the troop wants to come only for money. If [the caravan] does not fight them, [the troop] will not harm their bodies. Therefore it is not considered mortal danger.

Consequence: Therefore, if bandits attacked them and they settled with them (gave money so they will not harm them), we collect according to money.

Distinction: However, when they are lost in the Midbar [and must hire a guide], it says there that we collect also according to souls, for since they are lost, there is mortal danger.

Explanation (R. Tam): Aniyim who are close pay more than [Aniyim] far away, and similarly Ashirim who are close pay more than Ashirim far away;

However, Ashirim far away pay more than Aniyim who are close, for they collect according to wealth. (Rosh - they pay also based on distance. Surely, among people equally far away, people pay according to wealth. R. Yochanan teaches that among those of equal wealth, those closer pay [slightly] more. If plunderers find nothing in an Oni's house, surely they will go to another's house!)

Explanation: The verse above discusses [Tzadikim] - "v'Li Mah Yakru Re'echa Kel Mah Atzmu Rosheihem", and afterwards it says "Esperem me'Chol Yirbun."