On the way back from the sea it occurred to me to ask what I think should be simple to answer but I really do not know what could be the answer. in Bava Batra page 17 Abaye says the Mishna should read: “One must keep his pit three handbreadths from the wall of the pit of his neighbor,” not "from the pit of his neighbor." This seems like a direct proof of Rava that one should keep an object that can cause damage three handbreadths from the border line, even when there is nothing yet on the other side. How could Abaye understand his own statement according to his ruling that one can put that which causes damage next to the border of his neighbor until the neighbor put there something that can be damaged? (Rava said that one must keep one's object three handbreadths from the border, and this statement of Abayee help him directly.) However, later in the gemara, Rava explains the Mishna according to R. Jose to mean that the digging itself causes damage. I do not how that helps Abayee. If he means the wall itself is considered part of the pit that causes damage then he should say he can put it next to the border, and the other neighbor then has to keep his pit 6 handbreadths from the border. If on the other hand, he means only the hollow of the pit is what causes damage, then the way he reads the Mishna is his direct refutation. He said he can put something that causes damage next to the border. Not three handbreadths from the border. Furthermore, how can any of this relate to the Gemara later in the approach of Rabainu Ihzhak that holds if one did something slightly wrong by putting his object next to the border, then the other can do the same. Does that mean the wall does the damage? Then that is like what he said. But if he means the hollow of the pit, then the two pits would be joined into one pit. But this was already answered by Rava that it is the digging that causes the damage. But still, I do not see how that helps Abayee. Later note. After writing the above I saw that Tosphot asks this question and answers it. But let me state the actual Mishna and Gemara at this point to be clear. The Mishna says, “One must not dig a pit near the wall of his neighbor nor other type of thing that causes damage unless he moves away three handbreadths.” The Gemara asks “Why does the Mishna change from ‘pit’ to ‘wall’?” Abaye answered, “It means ‘the wall of the pit’”. The Gemara then asks, “If so, it should say, ‘One must not dig a pit near the pit of his neighbor unless he moved away three handbreadths’”. The Gemara answered, “It comes to tell us the wall of a pit is three handbreadths.” Tosphot says,” If it would say ‘the wall of the pit’ that would be proof to Rava and that is what the Gemara intends to ask. And then it answers for Abaye, “It means the normal wall of a pit is three handbreadths.” This answers the question to some degree. It means that all the other kind of objects that cause damage have to be three handbreadths from the object that can be damaged. But here both pits cause damage. Thus, it cannot say, “You cannot dig a pit three handbreadths from the other pit” because each pit is required to be moved three handbreadths totaling six in all. So, it says, “You cannot dig a pit (that is the hollow space of the pit) within three handbreadths of the wall of the other pit”, and thus the separation will be six handbreadths. The problem I still have on this is the point in the discussion “The Gemara then asks, “If so, it should say, ‘One must not dig a pit near the pit of his neighbor unless he moved away three handbreadths’ “That means if abaye right it should say a pit three handbreadths from the other pit. That is, one hollow of a pit is at the boundary and the other must be away three. But if Abayee is right, the other would have to be six away, not three, since each kind of damage must be three from that which can be damaged. The Mishna would have to be read, "One must move his pit six handbreadths from the pit of his neigbor" if Abyee would be right.I would like to answer this question but with some reservation. First let me say that in the approach of R. Jose there is first come first served (permission of who comes first) and if Abaye is going according to R. Jose then it is easy to see that if the Mishna would say one cannot dig a pit next to the pit of hi neighbor unless he moved away three handbreadths then that would mean there is permission of who came first. The first pit does not have to move and the second pit only has an obligation of moving three handbreadths away. If he de not want to be damaged by the first pit then it is his prerogative to move away further. However, this answer would only work if Abaye and r Jose agree. However, in Abaye himself, we do not see any kind of permission of first come first served. Only we ee if nothing else is next to the border, then he can put his thing there. But after something comes, we do not know what Abaye would say ______________________________________________________________________________________ On the way back from the sea it occurred to me to ask what I think should be simple to answer but I really do not know what could be the answer. In בבא בתרא י''ז אביי says the משנה should read: “One must keep his pit three טפחים from the wall of the pit of his neighbor,” not "from the pit of his neighbor." This seems like a direct proof of רבא that one should keep an object that can cause damage three טפחים from the border line, even when there is nothing yet on the other side. How could אביי understand his own statement according to his ruling that one can put that which causes damage next to the border of his neighbor until the neighbor put there something that can be damaged? However, later in the ,גמרא רבא explains the משנה according to ר' יוסי to mean that the digging itself causes damage. I do not how that helps אביי. If he means the wall itself is considered part of the pit that causes damage then he should say he can put it next to the border, and the other neighbor then has to keep his pit 6 handbreadths from the border. If on the other hand, he means only the hollow of the pit is what causes damage, then the way he reads the משנה is his direct refutation. He said he can put something that causes damage next to the border. Not three handbreadths from the border. Furthermore, how can any of this relate to the גמרא later in the approach of רבינו יצחקthat holds if one did something slightly wrong by putting his object next to the border, then the other can do the same. Does that mean the wall does the damage? Then that is like what he said. But if he means the hollow of the pit, then the two pits would be joined into one pit. But this was already answered by רבא that it is the digging that causes the damage. But still, I do not see how that helps אביי. Later note. After writing the above I saw that תוספות asks this question and answers it. But let me state the actual משנהand גמרא at this point to be clear. The משנהsays, “One must not dig a pit near the wall of his neighbor nor other type of thing that causes damage unless he moves away three handbreadths.” The גמרא asks “Why does the משנה change from ‘pit’ to ‘wall’?” אביי answered, “It means ‘the wall of the pit’”. The גמרא then asks, “If so, it should say, ‘One must not dig a pit near the pit of his neighbor unless he moved away three handbreadths’”. The גמראanswered, “It comes to tell us the wall of a pit is three handbreadths.” תוספות says,” If it would say ‘the wall of the pit’ that would be proof to רבא and that is what the גמרא intends to ask. And then it answers for אביי, “It means the normal wall of a pit is three handbreadths.” This answers the question to some degree. It means that all the other kind of objects that cause damage have to be three handbreadths from the object that can be damaged. But here both pits cause damage. Thus, it cannot say, “You cannot dig a pit three handbreadths from the other pit” because each pit is required to be moved three handbreadths totaling six in all. So, it says, “You cannot dig a pit (that is the hollow space of the pit) within three handbreadths of the wall of the other pit”, and thus the separation will be six handbreadths. The problem I still have on this is the point in the discussion גמרא then asks, “If so, it should say, ‘One must not dig a pit near the pit of his neighbor unless he moved away three handbreadths’ “That mean if אביי right it should say a pit three handbreadths from the other pit. That is, one hollow of a pit is at the boundary and the other mut be away three. But if אביי is right the other would have to be six away not three since each kind of damage must be three from that which can be damaged. The משנהwould have to be read one must move his pit six handbreadths from the pit of his neigbor if אביי would be right I would like to answer this question but with some reservation. First let me say that in the approach of ר' יוסי there is first come first served (permission of who comes first) and if אביי is going according to ר' יוסי then it is easy to see that if the משנה would say one cannot dig a pit next to the pit of his neighbor unless he moved away three handbreadths, then that would mean there is permission of who came first. The first pit does not have to move, and the second pit only has an obligation of moving three handbreadths away. If he does not want to be damaged by the first pit, then it is his prerogative to move away further. However, this answer would only work if אבייand ר' יוסי agree. However, in אביי himself, we do not see any kind of permission of first come first served. Only we ee if nothing else is next to the border, then he can put his thing there. But after something comes, we do not know what אביי would say