(Rav Nachman bar Yitzchak): Rav Huna admits that peddlers of the city cannot prevent traveling peddlers from selling their wares.

Ezra enacted that peddlers may go from city to city in order that cosmetics will be readily available to women.

They are allowed to go around the city and sell, but they may not fix a place to sell;

A Chacham is allowed to fix a place.

Rava allowed R. Yoshiyah and Rav Ovadyah to fix a place;

This is not (normally) the Halachah.

Question: Why did he allow them?

Answer: It was so they should not lose time from learning.

People selling baskets (some say - pots) came to Bavel. People of the city came to stop them.

Ravina: They came from elsewhere. They may sell to people from elsewhere who come on the market day;

They may sell only in the market. They may not go around the city.

People selling wool came to Pum Nahara. People of the city came to stop them.

Rav Kahana: They may stop you.

The sellers: We sold on credit. We must tarry here to collect the money (and we must sell for our livelihood)!

Rav Kahana: You may sell what is needed for your livelihood, but only for the time needed to collect your money.

Rav Dimi of Neharde'a brought dried figs on a ship.

The Reish Galusa (the executive head of Yisrael in exile, to Rava): See if he is a Chacham. If he is, give to him exclusive rights to sell figs.

Rava told Rav Ada bar Aba to test him.

Rav Ada: If an elephant swallowed a basket, and excreted it, does it still receive Tum'ah (or is it Tahor, like Kelim of dung)?

Rav Dimi did not know. Rav Ada teased him, and did not give to him exclusive rights to sell figs. The figs spoiled.

Rav Dimi complained to Rav Yosef.

Rav Yosef: Hash-m avenged the injustice done to the king of Edom. He will avenge your affliction.

"Pish'ei Mo'av... Lo Ashivenu" - they will be punished for burning the bones of the king of Edom.

Rav Ada died.

Rav Yosef: I am responsible, for I cursed him!

Rav Dimi: I am responsible. He was punished for the loss of my figs.

Abaye: I am responsible. He used to tell people 'rather than learn without satisfaction from Abaye, learn from Rava!'

Rava: I am responsible. He used to tell butchers that he will buy before my servant, for he is greater.

Rav Nachman bar Yitzchak: I am responsible.

Rav Nachman bar Yitzchak used to expound on Shabbos. Beforehand, he would review with Rav Ada. One day Rav Ada was detained by Rav Papa and Rav Huna brei d'Rav Yehoshua, who wanted to hear teachings of Rava that they had missed. The Talmidim asked Rav Nachman to begin.

Rav Nachman: I am waiting for the casket of Rav Ada.

Word spread that Rav Ada died.

Presumably, Rav Nachman bar Yitzchak was responsible.

(Mishnah): If Reuven's wall was near Shimon's wall (and it fell), he may not build another wall within four Amos.

If Reuven wants to build a wall opposite Shimon's window, the wall must be at least four Amos higher than or four Amos lower than the window, and (if it is higher) at least four Amos away from the window.

(Gemara): How was he allowed to build the first wall so close?

Answer #1 (Rav Yehudah): The Mishnah (does not discuss a wall that fell, rather it) says that he may not build a wall within four Amos.

Objection (Rava): The Mishnah says that he had a wall close to Shimon's wall!

Answer #2 (Rava): The Mishnah says, if Reuven's wall was four Amos away from Shimon's wall and it fell, he may not rebuild it within four Amos.

Question: What is the reason?

Answer: We want people to walk on the ground in between, this hardens the ground and strengthens the walls.

(Rav): The Mishnah only discusses a wall of a garden;

One may build a wall within four Amos of a wall of a Chatzer.

(R. Oshaya): The Mishnah discusses a wall of a garden or of a Chatzer.

(R. Yosi b'Rebbi Chanina): Rav and R. Oshaya do not argue;

Rav discusses an old city, in which the ground near the Chatzer walls is already hard (from years of trampling);

R. Oshaya discusses a new city, in which even the ground near the Chatzer walls is soft.

Question (Mishnah): If Reuven wants to build a wall near Shimon's window, the wall must be at least four Amos taller than or four Amos lower than the window, and at least four Amos away from the window.

(Beraisa): If it is taller, it must be enough taller so that he cannot crouch down from his wall and look into the window. If it is lower, it must be low enough so he cannot stand on his wall and see through the window. It must be far enough away, so it will not block light.

Inference: We are concerned only for blocking light, but not for trampling!

Answer: The case is, the wall is perpendicular to the existing wall. (Rashi - it inhibits treading only on a minute portion, i.e. the thickness of the new wall. Rashash - people will not walk near the old wall if they must then go around the new wall! Rather, if there was just enough room between the walls to squeeze through, people would do so for a shortcut, since it is cramped only for the thickness of the new wall.)

Question: The Beraisa did not say how far away the wall must be so that it will not block light!

(Rav Yeiva): One must distance the wall the width of the window.

Question: (Because it is close, even if it is higher,) Reuven will be able to look into the window!

Answer (Rav Zevid): The case is, Reuven slopes his wall so he cannot stand or lean on it.

Question: The Mishnah says that he must distance four Amos!

Answer: That is when he builds walls on both sides of the window;

If he only builds on one side, the width of the window suffices.

Question (Mishnah): One must distance a wall four Amos from a gutterpipe, in order that a ladder can be set up (to fix the pipe).

Inference: We are concerned only for the pipe, but not for trampling!

Answer: The case is, the pipe is (on a roof that is) inclined (and extends past the wall). There is room to walk underneath (the roof and next to the wall), therefore he must leave room only for the ladder.

(Mishnah): One must distance a ladder four Amos from a dovecote, in order that a marten (a weasel-like animal) cannot jump from it;

One must distance a wall four Amos from a gutterpipe, in order that a ladder can be set up.

(Gemara) Suggestion: Our Mishnah is not R. Yosi.

R. Yosi: says that each neighbor may dig or plant in his own property (he need not worry that damage will result to his neighbor).

Rejection: Even R. Yosi agrees to our Mishnah.

(Rav Ashi): R. Yosi admits regarding 'arrows' (i.e. damage that comes directly from the person's hand);

Here also, sometimes as he erects the ladder, the marten jumps from it.

Question: This is only Grama (causation. We do not obligate for damage through Grama!)

Answer (Rav Tuvi bar Masnah): This teaches that Grama of damage is forbidden.