the Gemara on page 23 in Bava Kama. Rambam according to the Gra.

As I was walking back from the sea it occurred to me why the Rambam held that Rava held that R. Yochanan holds that damage by fire is obligated because of damage by his property, not damage by his body. The reason is in the questions and answers of the Gemara on page 23 in Bava Kama. Abyee asked, if R Yochanan is right that damage by fire is because of “his arrows” {direct damage by his body}, then why would damage to hidden things not be liable? The abyee answered, there was a wall there, and it fell (not from the fire), and he did not have time to repair it before the fire broke out. So it is a case of not being able to do anything to stop that damage. [Even though we normally say a person is always liable to do damage, still damage by means of his property or (or even with fire which is more serious), the fact of the situation being totally out of one’s control makes him not liable. Rava then asks, if so, then even for open things he should be not liable. The Gemara answers R Yochanan holds damage by fire is considered “his arrows” and also his property; and our case where he liable for open things but not liable for hidden things is where there was neglect similar to what would be the case if he forgot to lock his ox up at night, and it went out and cause damage.] I think that the gemara considers a wall to be a case of not being able to change anything. but with no wall between him and his neighbor, if it would be “his arrows” then he would be liable for both open and hidden thing. [To get him to not be liable for hidden things the gemara has to come up with scenario where there was a wall. After all, arrows go far beyond walls. so the Rambam held that we no longer think that R Yochanan holds with “his arrows” except to make him liable in all the five kinds of damage that one is liable for in a case of damage by his body. Besides that, he is liable only for damage by his property. Just think. the Gemara said when there was a wall "his arrows were finished". So, to find a way that his arrows would not be finished, the Gemara had to extract the wall, and put in simple laziness and neglect. At that point, why would arrows be finished? Clearly not. I want to explain why the Gra wrote that only way to understand the subject on page 23 of Bava Kama is like the Rif and Rambam, that is that the Gemara decided that R Yochanan does no longer hold with his arrows except in so far as it makes him liable in another four types of damage. But in all other aspects, he holds like reish lakish that damage by fire is because of damage by mean of his property. The reason is this. Neither Abaye nor Rava had any problem with the idea that if one is liable because of his arrows that would extend beyond one’s own domain. The only question was it should even more liable for damage to hidden things. But then Abaye said the scenario is when there was a wall and so his arrows were finished. But Rava objected and said that then he wouldn’t be liable even for open things. So Rava decided the case is when there was no wall. But again, if there is no wall, then he should be liable for his arrows alone. There is no need to make him more liable because of damage by mean of his property. It was already perfectly fine for him to be liable for all damage done on another domain just from his arrow alone. so in short, the give and take questions and answers of Abaye and Rava make no sense unless you say that Rava held that R Yochanan hold his arrows are liable because of his money alone. His arrows would be finished if there was a wall there or if it fell and he had no time to repair it. But with no wall, there is no finishing of his arrows ------------------------------------- As I was walking back from the sea it occurred to me why the רמב''ם held that ר’ יוחנן changed his mind, and holds that damage by fire is obligated because of damage by his property, not damage by his body. The reason is in the questions and answers of the גמרא בבא קמא on page 23. אביי asked, if ר’ יוחנן is right that damage by fire is because of “his arrows” {direct damage by his body}, then why would damage to טמון hidden things not be liable? HE answers, there was a wall there, and it fell (not from the fire), and he did not have time to repair it before the fire broke out. So, it is a case of not being able to do anything to stop that damage(אונס) . [Even though we normally say a person is always liable to do damage, still damage by means of his property or (or even with fire which is more serious), the fact of the situation being totally out of one’s control makes him not liable. The רבא then asks, if so, then even for open things he should be not liable. The גמרא answers ר’ יוחנן holds damage by fire is considered “his arrows” and also his property; and our case where he liable for open things, but not liable for hidden things is where there was neglect. THAT WOULD BE similar to what would be the case if he forgot to lock his ox up at night, and it went out and caused damage.] I think that the גמרא considers a wall to be a case of not being able to change anything(אונס) . But with no wall between him and his neighbor, if it would be “his arrows”, then he would be liable for both open and hidden thing. [To get him to not be liable for hidden things the גמרא has to come up with scenario where there was a wall. After all, arrows go far beyond walls. so the רמב''ם held that we no longer think that ר’ יוחנן holds with “his arrows” except to make him liable in all the five kinds of damage that one is liable for in a case of damage by his body. Besides that, he is liable only for damage by his property. Just think. the גמרא said when there was a wall "his arrows were finished". So, to find a way that his arrows would not be finished, the גמרא had to extract the wall, and put in simple laziness and neglect. At that point, why would arrows be finished? Clearly not. I want to explain why the גר''א wrote that only way to understand the subject on page כ''ג of בבא קמא is like the רי''ף and רמב''ם , that is that the גמרא decided that ר’ יוחנן does no longer hold with his arrows except in so far as it makes him liable in another four types of damage. But in all other aspects, he holds like ריש לקיש that damage by fire is because of damage by mean of his property. The reason is this. Neither אביי nor רבא had any problem with the idea that if one is liable because of his arrows that would extend beyond one’s own domain. The only question was it should even more liable for damage to hidden things. But then אביי said the scenario is when there was a wall and so his arrows were finished. But רבא objected and said that then he wouldn’t be liable even for open things. So רבא decided the case is when there was no wall. But again, if there is no wall, then he should be liable for his arrows alone. There is no need to make him more liable because of damage by mean of his property. It was already perfectly fine for him to be liable for all damage done on another domain just from his arrow alone. so, in short, the give and take questions and answers of אביי and רבא make no sense unless you say that רבא held that ר’ יוחנן hold his arrows are liable because of his money alone. His arrows would be finished if there was a wall there or if it fell and he had no time to repair it. But with no wall, there is no finishing of his arrows