1)

(a)A 'Lechi ha'Omed Me'elav' - is a Lechi that happens to be correctly placed to serve as a Lechi, but that was not put there to serve as a Lechi.

(b)Rav holds - that a 'Lechi ha'Omed Me'elav' is not a Lechi; Abaye agrees with that if there was another Lechi in place when Shabbos entered, so that that Lechi was not needed.

(c)According to the contention that their dispute extends to a Mechitzah ha'Omedes Me'eleha - Rava will have to establish the Mishnah in Succah (which permits a Succah whose walls consist of trees), by trees that were specifically planted for that purpose. The Chidush is that we do not invalidate such a Sucah, for fear that one may come to use the tree (i.e. to climb it and break away a branch).

(d)Rava will explain the Beraisa 'Hayah Sham Geder O Chitzas ha'Kanim, Nidon Mishum Deyumad' - in the same way as he explained the Mishnah in Succah - namely, that the Geder or the Chitzas ha'Kanim were planted specifically to serve as Deyumdin. The Chidush is that a wall made up of canes spaced within three Tefachim of each other, and which is considered a wall only because of Levud, is Kasher by Pasei Bira'os, too. A Deyumad is two adjacent post of at least one Amah each. Four of these dual posts serve as walls for Pasei Bira'os, which will be explained in detail in the following Perek.

2)

(a)An 'Ilan ha'Mesach al ha'Aretz' - is a tree with wide overhanging branches. Carrying underneath it is permitted - provided its branches reach to within three Tefachim of the ground, and according to Rava (at this stage), it was specifically planted to use in this manner on Shabbos.

(b)The reason that carrying underneath it is restricted to a Beis Sasayim (which is not the case by a house), is because this is a 'dwelling that is made to serve the outside' (i.e. because it is uncomfortable to stay out in the field - not because that is where he lives), as opposed to a house, where it is the field which serves the house, and not vice-versa.

(c)A Beis Sasayim comprises fifty by a hundred Amos (the same area as the Chatzer of the Mishkan).

3)

(a)'Shavas be'Tzel she'Hu Gavo'a Asarah ... ve'Chen be'Neka she'Hu Amok Asarah ... ' - teaches us that if someone finds himself on a large mound of earth (over ten Tefachim high and between four Amos square and a Beis Sasayim in area, or in a ditch of similar dimensions) when Shabbos enters, he is permitted to walk that entire area, and to consider it his home, to walk two thousand Amos in all directions, because he has encamped in a Reshus ha'Yachid - the former case due to 'Gud Asik Mechitzos.

(b)'Kamah Ketzurah, ve'Shibalos Makifos Osah' - refers to a field of standing corn, where an area in the middle has been cut; the standing corn that surrounds it constitutes Mechitzos, and one is permitted to walk there, as well as to walk two thousand Amos in all directions. This does not present Rava with a problem - because the cut area could easily have been prepared deliberately for that purpose.

(c)A mound of earth and a ditch (in those days) would hardly have been man-made, in which case, they were clearly not made specifically as Mechitzos. Consequently, according to Rava (who currently extends the Din of 'Lechi ha'Omed Me'elav' to Mechitzah), why should they be considered Mechitzos?

(d)We are therefore forced to concede - that the Machlokes between Abaye and Rava (with regard to 'Lechi ha'Omed Me'elav') is confined to a Lechi, and does extend to a Mechitzah.

4)

(a)Abaye, who holds that 'Lechi Mishum Mechitzah', permits a Lechi that happened to be strategically placed, just like a Mechitzah would be Kasher in such a case; whereas Rava, who holds that 'Lechi Mishum Heker' - will invalidate a Lechi that was not placed there deliberately, because that does not constitute a Heker.

5)

(a)We may have thought that stones which protrude from a wall at different widths cannot serve as a Lechi, even where there is less than three Tefachim between one stone and the next - because, since builders usually build the ends of walls in this way, when they have in mind to extend them to the wall opposite, people will think that that is what is intended here, which leaves us without a Heker (and Rav holds that 'Lechi Mishum Heker'). Nevertheless, the Beraisa teaches us that, since this wall was built specifically as a Lechi, it is Kasher.

(b)The Beraisa too, of 'Kosel she'Tzido Echad Kanus me'Chavero, Bein she'Nir'eh mi'Bachutz ve'Shaveh mi'Bifenim, u'Vein she'Nir'eh mi'Bifenim ve'Shaveh mi'Bachutz, Nidon Mishum Lechi' - speaks according to Rava, when the extra section of wall was specifically built as a Lechi, and the Chidush is that 'Nir'eh mi'Bachutz ve'Shavah mi'Bifenim, Nidon Mishum Lechi'.

6)

(a)When the Lechi broke just as the servant was bringing Rav some water - Rav hinted to him to stop walking (and to put down the jar of water where he was).

(b)He did not want to rely on the date-palm that was growing at the entrance of the Mavoy - because they had not relied on it before Shabbos (i.e. there was another Lechi there when Shabbos came in).

(c)The Gemara thought - that Abaye and Rava were arguing over a Lechi which they did not rely on before Shabbos, and which Abaye permitted. In that case, the incident with Rav would support Rava.

(d)No, answers the Gemara - their dispute was specifically in a case where they did rely on the Lechi (i.e. where there was no other Lechi there before Shabbos), in which case, both Abaye and Rava would conform with the ruling of Rav. This is one of the six cases of 'Ya'al Ke'Gam', by which we rule like Abaye.

7)

(a)According to the Chachamim - an animal can be used as a Lechi, is Metame if it is used as a Golel, and is valid as a Get, if a Get is written on it.

(b)a Golel - is the lid of a coffin (according to Rashi).

8)

(a)Rebbi Meir also disqualifies an animal from being used as the wall of a Succah, and of a Mavoy.

(b)According to Rebbi Yossi ha'Gelili, a 'Sefer' in the Parshah of Sotah means is a scroll of parchment (to exclude a live animal), and even after we include other things from "ve'Kasav Lah", we learn from Sefer to exclude living creatures. The Rabbanan however - argue, that the Torah did not write "ve'Kasav ... ba'Sefer", but "Sefer", from which we can learn that the husband must write the divorce statement (from the word 'Saper' - to tell).

(c)If not for the Pasuk ve'Kasav Lah", we would have thought that a man can divorce his wife by giving her money - from the Hekesh "ve'Yatz'ah ve'Haysa" (which compares the divorce to the Kidushin - just as the latter can be effected with money, so too, can the former).

9)

(a)Rebbi Yossi ha'Gelili learns the above Din from "Sefer Kerisus" - 'Sefer Korsah, ve'Ein Davar Acher Korsah'.

(b)The Rabbanan learn from "Sefer Kerisus" - Davar ha'Kores Beino le'Veinah' (meaning that he must break with her, and not be permanently bound to her by some condition or other.

(c)The Rabbanan - do not make any Derashos from 'Kares-Kerisus'. According to them, 'Kerisus' is normal phraseology.

(d)A condition that would be effective by a Get - for example, would be 'if he were to divorce his wife on condition that she does not go to her father's house for thirty days.

10)

(a)It will be permitted to carry inside an encampment consisting of a circle of wagons and their paraphernalia - provided that a. the wall in question is at least ten Tefachim high - and b. the gaps do not total more than the standing wall.

(b)A breach of up to ten Amos is considered an entrance, one of more than ten Amos is not.

11)

(a)Rav Papa permits 'Parutz ke'Omed' - because, in his opinion, Hash-m told Moshe on Sinai not to leave more breaches than standing wall; Rav Huna Brei de'Rav Yehoshua forbids it - according to him, Hash-m told Moshe to leave more standing wall than breaches.

(b)'ve'Lo Yihyu Pirtzos Yeseiros al ha'Binyan' - implies that if the breaches are not more than the wall (but only equal), then it is Kasher (a proof for Rav Papa).

(c)According to Rav Huna Brei de'Rav Yehoshua - the Mishnah should have said 'Lo Yihyu Pirtzos ke'Binyan'.

12)

(a)'ha'Mekareh Succaso bi'Shefudin O ba'Aruchos ha'Mitah, Im Yesh Revach Kamosan, Kesherah' - also appears to prove the opinion of Rav Papa.

(b)The Gemara initially understood 'ke'she'Nichnas ve'Yotze' - to mean that 'Revach Kamosan' automatically means that one leaves plenty of room to place Sechach the same width as the rods, because of the difficulty of fitting them in. Consequently, the Gemara asks 've'Ha Efshar Letzamtzem' - why should it be so difficult to fit the Sechach in gaps the same size as the rods, if just the right amount of space is left for them (meaning that there is no reason why 'Kamosan' should not be taken literally)?

(c)Rebbi Ami answers by establishing the Mishnah by 'Ma'adif' - meaning that the Mishnah speaks when they left plenty of room to fit the Sechach - easily (not because they had to, but because they wanted to).

(d)Rava establishes the Mishnah - by Sechach that is placed not parallel to the rods, but adjacent to them. In that case, there will automatically be more Sechach than rods. Why is that? Because each piece of Sechach stretches from the top of one rod to the top of the next one.