Bava batra page 18b.The approach of Rabainu Izhak.

if you go with Rabainu Izhak, then you have to say that the only allowance according to r Jose is in a case of a sale and this would apply both in the case of the bees and mustard and in the case of the tree and pit. the reason is that here on page 18 the whole question on Rava from R. Jose was that Rava has to hold with his law whether according to the sages or to r Jose. and so, our question on Rava was from r Jose since we already answered him according to the sages. now Rav Papa said the answer is that R. Jose said his law only in a case of a sale. But then we ask on that. For then, what could be the reason of the sages in the case of the tub of linen or even this case of the mustard? In other words, when R. Jose disagrees with the sages, they have to be talking about the same case. Otherwise, R. Jose would have said "I disagree with you only in a case of a sale." And now our answer is that R. Jose said his law in the case of a sale, and otherwise he would say like Rava that anything that can cause damage must be removed away from the border of one's neighbor three handbreadths even when there is nothing yet on the other side of the border. Then comes the major point of Rabbainu Izhak. That is that Ravina is just a continuance of the answer of Rav Papa. And he said that the sages said one that causes damage must be removed from the border, and that R. Jose said that the thing that can be damaged must be removed from the border. And since this is a continuance of the answer of Rava Papa, this means that R. Jose said this only in the case of sale. But in a case where there are just two neighbors, each one must keep his object that can cause damage away from the border. This means that if the law would be like Rabbainu Izhak, then even though the law is like R. Jose, that is only in a case of a sale, but otherwise anything that can cause damage must be kept away from the border. And since the whole point of this discussion is so that there should be no disagreement between R. Jose and Rava, this same reasoning applies on page 25 with the tree and pit. There the sages said the tree must be cut down if it is with 25 cubits of the pit unless it was there first. And R. Jose said it does not need to be cut down since each is in his own domain. And here also the case is that of a sale which is the only case that R Jose holds his law, and the sages said their law in the case of a sale also. Now it is not possible that what they said if the tree was there first it can stay, because that would contradict the law of Rava that whatever can cause damage has to be kept way from the border even when there is nothing on the other side of the border that could be damaged. _____________________________________________________________________________ if you go with רבינו יצחק, then you have to say that the only allowance according to ר' יוסי is in a case of a sale and this would apply both in the case of the bees and mustard and in the case of the tree and pit. The reason is that here on page י''ח the whole question on רבא from ר' יוסי was that רבא has to hold with his law whether according to the חכמים or to ר' יוסי. and so, our question on רבא was from ר' יוסי since we already answered him according to the חכמים. Now רב פפא said the answer is that ר' יוסי said his law only in a case of a sale. But then we ask on that. For then, what could be the reason of the חכמים in the case of theמישרה or even this case of the mustard? In other words, when ר' יוסי disagrees with the חכמים, they have to be talking about the same case. Otherwise, ר' יוסי would have said "I disagree with you only in a case of a sale." And now our answer is that ר' יוסי said his law in the case of a sale, and otherwise he would say like רבא that anything that can cause damage must be removed away from the border of one's neighbor three handbreadths, even when there is nothing yet on the other side of the border. Then comes the major point of רבינו יצחק. That is, that רבינא is just a continuance of the answer of רב פפא. And he said that the חכמים said one that causes damage must be removed from the border, and that ר' יוסי said that the thing that can be damaged must be removed from the border. And since this is a continuance of the answer of רב פפא, this means that ר' יוסי said this only in the case of sale. But in a case where there are just two neighbors, each one must keep his object that can cause damage away from the border. This means that if the law would be like רבינו יצחק, then even though the law is like ר' יוסי, that is only in a case of a sale, but otherwise anything that can cause damage must be kept away from the border. And since the whole point of this discussion is so that there should be no disagreement between ר' יוסי and רבא, this same reasoning applies on page כ''ה with the tree and pit. There the חכמיםsaid the tree must be cut down if it is with כ''ה cubits of the pit unless it was there first. And ר' יוסי said it does not need to be cut down since each is in his own domain. And here also the case is that of a sale which is the only case that ר' יוסי holds his law, and the חכמים said their law in the case of a sale also. Now it is not possible that what they said if the tree was there first, it can stay, because that would contradict the law of רבא that whatever can cause damage has to be kept away from the border even when there is nothing on the other side of the border that could be damaged. The whole point of our discussion is that there should be no contradiction from the חכמים or from ר' יוסי on the law of רבא