1)

(a)A wall of ladders between two courtyards which is more than ten Amos long would be Pasul if a ladder was considered a Pesach, since one Chatzer which opens completely into another forbids them to carry (and we learnt above that a ladder between two courtyards has the Din of a Pesach).

(b)The reason that they are considered two courtyards is because we only consider a ladder a Pesach, le'Kula (as we learnt at the end of the previous Amud), when it is less than ten Amos, but not Lechumra, when it is more. In that regard, we consider it a Mechitzah.

(c)This clashes with the statement that Shmuel himself made earlier, where he said 'Anshei Chatzer ve'Anshei Mirpeset, she'Shachechu ve'Lo Ervu ... Oseres', which we initially think is Asur because the ladder negates the Din Mechitzah - whereas we are now saying that the ladder does not negate the Din of Mechitzah.

2)

(a)The problem Abaye had with Kakunai was the houses at the edge of the town, which faced the river, and which had no doorways facing the town.

(b)Abaye rejected the idea of ...

1. ... being Me'arev the town and leaving those houses as the Shi'ur - because our Mishnah writes 'Ein Me'arvin es Kula', implying that they could have been Me'arev those houses, had they wanted to, but that they chose to preclude them; whereas the houses in Kukinai, which had no doorways facing the town, could not have combined in their Eruv, even if they had chosen to do so.

2. ... making windows which opened out to the town - because he proved from Rabah bar Avuha, who was Me'arev the town of Mechuza area by area, by means of the deep trenches for the date-pits for the animals - that his original contention was wrong. In that case, due to the deep trenches, the areas of Mechuzah would not have been able to make a combined Eruv even if they had wanted to. Consequently, building windows facing the town was unnecessary.

(c)Then Abaye argued that the windows should be necessary after all (like he initially inferred from our Mishnah), and that there was no proof from the case of the Mavo'os of Mechuzah, because even though the trenches rendered one area inaccessibly to the other, Mechuzah had a system of bridges which linked the rooftops of the different areas to one another.

(d)Abaye's final proof that the windows were not necessary - was from Pumbedisa, where they made an Eruv (although it was initially an Ir shel Rabim), on the basis of the Shi'ur of a hut for straw that belonged to Mar bar Pupidsa, even though the hut had neither windows nor doors facing the house.

3)

(a)The fifty residents outside the town required by Rebbi Yehudah as the Shi'ur - includes women and children, since the Beraisa explicitly states this to have been the case with Chadashah.

(b)It is obvious that an Eruv would be effective in Chadashah itself - because why should not serve as a Shi'ur for Chadashah just as Chadashah served as a Shi'ur for it?

(c)The dispute between Rav Huna and Rav Yehudah regarding a town like Chadashah - is based on whether a small town like Chadashah, requires a Shier like a large one or not.

4)

(a)Rebbi Yitzchak concludes that an Ir shel Rabim ve'Na'asis shel Yachid is permitted to make a collective Eruv - even with a Shi'ur of one house in one Chatzer, though it is not clear how an Amora has the authority to argue with Tana'im (see Rosh Siman 11)

5)

(a)If on Friday afternoon, someone who is two thousand Amos east of his house, asks his son to place an Eruv one thousand Amos beyond his house to the west - he is permitted to walk from where he is to his house (meaning that his house remains his central point, as before).

(b)This is different than a traveler who fixes an unspecified point under a tree which is two thousand Amos from where he is, and who has no Eruv at all (because he gave up his original Makom Shevisah, and his new one is not Koneh for him) - because someone who is arranging an alternative Eruv from his home, probably has in mind to retain his Makom Shevisah unless he is Koneh elsewhere.

(c)The closest to the town that an Eruv is valid - is outside the Ibur (any residence within seventy and two thirds Amos of the town's limits).

6)

(a)'Mi she'Hayah be'Mizrach, ve'Amar li'Veno Arev Li be'Ma'arav; Im Yesh ... le'Eruvo Alpayim Amah u'le'Veiso, Yeser Mikahn, Asur le'Veiso, u'Mutar le'Eruvo'. If he is standing east of his house, and he instructs his son to make an Eruv on the west - then how is it possible, asks the Gemara, for his house to be further from him than the Eruv?

(b)Firstly, answers the Gemara - 'to the east', does not mean to the east of his house, but to the east of his Eruv. And secondly, even if east means east of his house, it does not mean due east, but diagonally (north-east or south-east), whereas his Eruv is placed only fractionally to the west of his house; however, since it is due east from where he is standing, it is still closer than his house.

7)

(a)When our Mishnah says that if someone places one's Eruv even one Amah outside the Techum, what he gains on one side, he loses on the other - it means that if he places his Eruv to the east of the town, one Amah beyond the Ibur, then he will be allowed to walk one Amah less than his original two thousand Amos to the west.

(b)When the Beraisa states that he loses the entire town, because the town is included in the reckoning - it means to say that whereas initially, he was able to reckon the town as four Amos, leaving him two thousand Amos outside the town, now that he has made a new Eruv far from the town, wherever his Eruv now ends in the town, is the limit of his Eruv (and he can no longer reckon the town as four Amos, to go beyond it the remaining Amos minus four (which constitutes the town).

(c)Our Mishnah, which does reckon the town as four Amos (like it was before he made his new Eruv) - speaks when his two thousand Amos ends at the far extremity of the town (i.e. it includes the entire town). In that case, we learn from Rebbi Yehoshua ben Levi, that we still reckon the entire town as four Amos.

8)

(a)When Rebbi Idi said about Rebbi Yehoshua ben Levi's two Dinim 'Ein Elu Ela Divrei Nevi'us' - he meant to say that, although the statements were certainly made responsibly (he obviously heard them from his Rebbe), nevertheless they are like prophesies, since he issued them without any reason (and they are difficult to comprehend).

(b)Not at all, retorted Rava, since both statements are clearly stated in a Mishnah.

(c)The text of the Mishnah, according to Rava reads 'Anshei Ir Gedolah Mehalchin es Kol Ir Ketanah, ve'Ein Anshei Ir Ketanah Mehalchin es Kol Ir Gedolah', and the reason for the difference is - because, whereas the two thousand Amos of the large town end at the far end of the small town, the two thousand Amos of the large town end in the middle of the large one - exactly as Rebbi Yehoshua ben Levi said. (This is feasible when one considers that initially, both towns reckon the entire town as four Amos).

(d)According to Rav Idi, the Mishnah reads 'Anshei Ir Gedolah Mehalchin es Kol Ir Ketanah, ve'Anshei Ir Ketanah Mehalchin es Kol Ir Gedolah', and we are speaking here, not about measuring two thousand Amos (which is what Rebbi Yehoshua ben Levi is referring to), but to someone who places his Eruv in another town, and there, everyone agrees that the entire town is considered to be four Amos.