Shall we say that this baraita, which teaches that they are all liable, is in accordance with the opinion of Rabbi Yehuda HaNasi, who holds both liable for digging, and this baraita, which holds the latter liable, is in accordance with the opinion of the Rabbis, who hold only the last one liable?

Rav Zevid said: Both this baraita and that baraita are in accordance with the opinion of the Rabbis. The way the first baraita accords with their opinion is that the Rabbis say that the last one is liable only where the first one did not make the pit of sufficient measurement to cause death, but dug less than ten handbreadths. But where the first one made a pit of sufficient measurement to cause death, such as in this case, where the first one dug ten handbreadths himself and it was subsequently deepened further by others, even the Rabbis concede that they are all liable.

The Gemara asks: But in the second baraita, where he plastered and cemented it, the first made a pit of sufficient measurement to cause death, and nevertheless, the baraita teaches that the last person is liable. They said in response: There it is referring to a case where the pit did not have fumes capable of leading to death, since it was very wide. And then the other came, and by narrowing it with plaster and cementing it, he added to it the characteristic of having fumes capable of leading to death.

There are those who say that this is what Rav Zevid said: Both this baraita and that baraita are in accordance with the opinion of Rabbi Yehuda HaNasi. This first baraita, which teaches: They are all liable, fits well with his opinion. That second baraita, which teaches: The last one alone is liable, is referring to a case where the pit did not have sufficient fumes in it that were capable of leading to either death or damage, and then another person came and by narrowing it with plaster and cementing it, he added to it the characteristic of having fumes capable of leading to both death and damage.

Elaborating on this subject, Rava says: With regard to one who placed a stone at the opening of a pit less than ten handbreadths deep and brings the pit to a depth of ten handbreadths by raising the ground next to the opening of the pit, we have arrived at the dispute between Rabbi Yehuda HaNasi and the Rabbis concerning whether only the second or both are responsible for damage caused.

The Gemara asks: Isn’t this obvious? This is precisely the case they are disputing, so what does Rava’s statement add to this? The Gemara answers: Lest you say that there is a distinction between a person deepening a pit at the bottom, in which case it is his lethal fumes that he caused that kill the animal, but if he added to the pit at the top, where it is not his lethal fumes that kill the animal, say that he would not be liable. Rava’s statement teaches us that the last one is liable, and this case is subject to dispute between Rabbi Yehuda HaNasi and the Rabbis as to whether only the last one or both are liable.

Rava raises the following dilemma: If someone dug another handbreadth in a pit that was nine handbreadths deep, so that it reached a depth of ten handbreadths, and subsequently closed up that handbreadth inside the pit, or if he removed his stones that he had placed at the opening of the pit so that the depth of the pit was reduced to less than ten handbreadths, what is the halakha? Do we say that what he did to increase the depth of the pit to ten handbreadths, he has removed, and restored the initial situation that existed before he dug the extra handbreadth, causing responsibility for damage to revert solely to the original digger?

Or perhaps, by closing it up, he removed the action of the first digger, since he has removed the ability of the pit to cause death? If so, it moves entirely into his possession and he now assumes full responsibility for the pit of nine handbreadths. The Gemara concludes: The question shall stand unresolved.

§ Rabba bar bar Ḥana says that Shmuel bar Marta says: With regard to a pit that is eight handbreadths deep and two handbreadths of it contain water, one is liable for it. What is the reason? Each handbreadth of water is like two handbreadths of dry space. Therefore, the pit is effectively ten handbreadths in depth and contains a sufficient quantity of lethal fumes to render its owner liable.

A dilemma was raised before the Sages: If a pit is nine handbreadths deep, and from that measurement, one handbreadth contains water, what is the halakha? Is this case equivalent to the previous one? Do we say that since there is not as large a quantity of water as in the case stated by Rabba bar bar Ḥana, the pit does not have a sufficient quantity of lethal fumes to render the digger liable? Or perhaps it can be argued that since the pit is deeper than the one in the previous case, it does have lethal fumes, despite containing less water?

Similarly, the following question can be raised: What is the halakha if a pit is seven handbreadths deep and three of the handbreadths contain water? Do we say that since there is a much larger quantity of water in this case, it is equivalent to a pit of ten handbreadths and therefore has lethal fumes, or perhaps since it is not as deep, it does not have a sufficient quantity of lethal fumes to render the digger liable? The Gemara concludes: The question shall stand unresolved.

Rav Sheizevi asked the following question of Rabba: If one widened the opening of a pit that was already ten handbreadths deep, what is the halakha? Rabba said to him: By doing so, he has actually reduced the lethal fumes and has not worsened the situation. Therefore, he should not be liable. Rav Sheizevi said to him: On the contrary, by widening the opening of the pit, he has brought the potential for damage closer to an animal that might fall inside.

Rather, Rav Ashi said concerning this question: Let us see: If the animal died because of the lethal fumes, the one who widened the pit should be exempt, since he reduced the lethal fumes. But if the animal died because of the impact, he should be liable, since he has brought the potential for damage closer to it. There are those who say that Rav Ashi said: Let us see: If the animal fell on that side that he widened, then his action has brought the potential for damage closer, and so he should be liable. But if the animal fell on the other side, he should bear no responsibility, since he reduced the lethal fumes.

It was stated: With regard to a pit whose depth is equal to its width, Rabba and Rav Yosef both say a ruling in the name of Rabba bar bar Ḥana, who says it in the name of Rabbi Mani, but each present it differently. One of them says: A pit always contains a quantity of lethal fumes sufficient for liability, unless its width is greater than its depth. Therefore, when they are equal, the digger is liable. And one says: A pit never contains a quantity of lethal fumes sufficient for liability, unless its depth is greater than its width. Consequently, when they are equal, the digger is exempt.

§ The mishna teaches that if the first partner passed by the pit and did not cover it, and then the second also passed by it and did not cover it, the second is liable. The Gemara asks: And from what point is the first exempt from responsibility for the pit? Rabba and Rav Yosef both say a ruling in the name of Rabba bar bar Ḥana, who says it in the name of Rabbi Mani, but each one presents it differently: One says: From the time he leaves the other partner using it, and one says: The first is absolved of responsibility only when he conveys to him his bucket, with which he will draw water from the pit.

The Gemara notes: This dispute is like a dispute between tanna’im, as it is taught in a baraita: With regard to one who draws water from a cistern, and his friend comes and says to him: Leave me and I will draw water, once the first person leaves the second person while the second is using the cistern, the first is now exempt if he did not cover it. Rabbi Eliezer ben Ya’akov says: The first person is not absolved of responsibility until the time when he conveys his bucket to the second person.

The Gemara clarifies the dispute: With regard to what principle do they disagree? Rabbi Eliezer ben Ya’akov maintains that there is a legal concept of designation. According to this principle, a situation in which certain aspects were not initially clearly defined can become clarified retroactively after a certain action or event occurs. The halakha treats all the aspects as being clearly defined and identifiable from the outset.

In this case, the water is considered divided between the partners even before they draw it. When they do draw it, it is treated as if this one were filling from his part, the location of which has now been determined retroactively, and this one were filling from his part. Therefore, as long as the first partner has not conveyed his bucket to the second, he, as an owner of a defined part of the water, has not absolved himself of responsibility for the cistern. And by contrast, the Rabbis maintain that there is no designation and they both have the right to draw water from the cistern. Therefore, as soon as the second partner is left alone to draw water, he is responsible for the cistern and all the water it contains, even without conveying the bucket.

Ravina said: And in this regard, they follow their lines of reasoning in an analogous case, as we learned in a mishna (Nedarim 45b): With regard to the case of partners that vowed not to derive any benefit from each other, it is prohibited for them to enter their jointly owned courtyard, as this would violate their vows. Rabbi Eliezer ben Ya’akov says: It is permitted for them to enter the courtyard, since this one enters into his portion of the courtyard and that one enters into his portion.

The Gemara explains: With regard to what principle do they disagree? Rabbi Eliezer ben Ya’akov maintains that there is retroactive designation, and retroactively the section of the courtyard that each one enters becomes the portion that belongs to him. Therefore, this one enters his part, and that one enters his part. By contrast, the Rabbis maintain that there is no retroactive designation, and each portion of the courtyard belongs jointly to both.

§ Having mentioned this halakha concerning conveying a bucket to transfer responsibility for the pit, the Gemara cites that which Rabbi Elazar says: With regard to one who sells a cistern to another, once the seller conveys his bucket to the buyer for drawing water from the cistern, the buyer acquires the cistern. The Gemara asks: What are the circumstances? How does conveying the bucket serve to effect acquisition of the cistern? If he is acquiring the cistern by means of paying money, let him acquire it with money that he paid. If he is acquiring the cistern by means of taking possession, then let him acquire it by taking possession, which is accomplished by using it.

The Gemara answers: Actually, the case is where the cistern was acquired through taking possession, and in that case, the seller usually must say to him: Go, take possession, and thereby acquire it for yourself. And in this case, when he conveys his bucket to him, he is like one who says to him: Go, take possession, and thereby acquire it. Therefore, once he begins drawing water from the cistern, he has acquired it through taking possession.

The Gemara cites a related ruling: Rabbi Yehoshua ben Levi says: If one sells a house to another,