1)

(a)The Mishnah discusses someone who has been forcibly taken and placed outside his T'chum on Shabbos by Nochrim or via a Ru'ach Ra'ah - (i.e. he is possessed by a Sheid [a demon]).

(b)The Tana - prohibits him from walking beyond his four Amos.

(c)If however, they duly returned him to his original location - it is as if he had never left it (and the entire town has a Din of four Amos as it did before he left it).

(d)If however, he ...

1. ... went outside the T'chum of his own volition (even if was forcibly returned) or if he ...

2. ... returned of his own volition (even after being forcibly taken outside the T'achum) - he is forbidden to go outside his four Amos.

2)

(a)If the robbers or the Ru'ach Ra'ah carried him to a walled city or deposited him (See Tos. Yom-Tov) inside a large pen ('Dir' or 'Sohar' See Tiferes Yisrael) - then the city or pen have a Din of four Amos, and he is free to walk wherever he wishes within its walls.

(b)Rebbi Yehoshua and Rebbi Akiva nevertheless restrict him to his four Amos, either because, since he did not 'rest' within the air of the Mechitzos before Shabbos, the Mechitzos will not affect him, or - because they decreed a pen on account of an open valley (See Tos. Yom-Tov).

3)

(a)When it says 've'Hifligah Sefinasam ba'Yam', it means that they left the sea shore toward the sea.

(b)Raban Gamliel and Rebbi Elazar ben Azaryah walked around the entire ship - because, despite the fact that the ship went beyond the T'chum on Shabbos, a. it was transporting them forcibly and b. since the ship had walls, it was as if it had transported them to a walled pen.

4)

(a)Rebbi Yehoshua and Rebbi Akiva declined to walk more than four Amos - because they wanted to be Machmir on themselves (See Tos. Yom-Tov).

(b)We might have thought that specifically Rebbi Yehoshua and Rebbi Akiva had a Halachic basis for their stringent ruling - because in the previous case, they forbade walking more than four Amos even in a pen.

(c)There are two reasons as to why this is not the case; one of them, because as long as the ship was moving, there was no reason to forbid it (See Tos. Yom-Tov), the other - because they had acquired their places (Koneh Shevisah) on the ship before Shabbos arrived.

(d)The Halachah in both cases is - like Raban Gamliel and Rebbi Elazar ben Azaryah.

5)

(a)On another occasion, the ship on which the Tana'im were travelling only arrived at the port after Shabbos had entered. They asked Raban Gamliel - whether they were permitted to disembark and to enter the town ...

(b)... since they were not sure as to whether they entered T'chum Shabbos before or after Shabbos arrived.

(c)He permitted them to disembark - because he assessed that they had entered the T'chum before Shabbos arrived.

(d)He knew that - by means of a primitive telescope made of a hollow bamboo.

(e)The city at which they arrived cannot have been walled - because if it was, the assessment would not have been necessary, any more than a walled pen, which Raban Gamliel himself permitted anyway.

6)

(a)The Mishnah now discusses someone who left the T'chum Shabbos 'with permission' - (e.g to testify that he saw the new moon or to save somebody from a group of Nochrim or his field from a flood) ...

(b)... but when he arrived at his destination - he discovered that his services were no longer required.

(c)The Tana - allows him to walk two thousand Amos in all directions (from the spot where he receives the information).

(d)What he adds ...

1. ... 'Im Hayah be'Soch ha'T'chum, ke'Ilu Lo Yatza', he means - that if that spot is within two thousand Amos of his house, it is as if he did not leave his house.

2. ... 'she'Kol ha'Yotz'in Lehatzil, Chozrin li'Mekoman', he means - that the current leniency is similar to the leniency which allows someone who left his T'chum Shabbos to save from a band of Nochrim or from an earthquake to return with his weapons and tools (See Tos. Yom-Tov).

7)

(a)The problem Rebbi Meir has with a traveler who stops to rest on Friday afternoon before Shabbos enters, and when, after nightfall, he proceeds on his way, he discovers that he is within the T'chum of a town is - that in his opinion, one cannot be Koneh Shevisah without one's knowledge.

(b)When he says 'Lo Yikaneis', he means - that he cannot consider himself like a resident. Rather he is only permitted to walk two thousand Amos from where he slept (See Tos. Yom-Tov).

(c)According to Rebbi Yehudah - he may enter the town and consider himself like a resident (who is permitted to walk anywhere in the town and two thousand Amos beyond its borders.

(d)Rebbi Yehudah proves his opinion from Rebbi Tarfon - to whom this once happened, and he practiced the Halachah that way.

8)

(a)According to Rebbi Yochanan ben Nuri, a traveler who falls asleep on Friday afternoon and is unaware when Shabbos enters, nevertheless has two thousand Amos from the spot where he fell asleep. The Chachamim - allow him only four Amos ...

(b)... which they learn from the Pasuk in Beshalach (in connection with the Manna) - "Sh'vu Ish Tachtav" ...

(c)... which teaches us that every person is granted four Amos space in the street - since the average height of a person is three Amos, and when he lies down, he has an additional Amah to stretch his arms and legs.

(d)The basis of their Machlokes is ' whether objects that are Hefker (which, like a sleeping person have no Da'as, are Koneh Shevisah (to be taken two thousand Amos (Rebbi Yochanan ben Nuri), or whether they share the T'chum of whoever acquires them on Shabbos (the Rabbanan).

(e)The Halachah regarding ...

1. ... objects that are Hefker is - like the Chachmim (that objects of Hefker are not Koneh Shevisah).

2. ... a sleeping person - like Rebbi Yochanan ben Nuri (that a sleeping person is Koneh Shevisah [See Tos. Yom-Tov]).

9)

(a)When Rebbi Eliezer says "ve'Hu be'Emtza'an', he means - that his four Amos constitute two in each direction.

(b)Rebbi Yehudah concedes (See Tos. Yom-Tov) - that he must initially choose the direction that he wants to take advantage of, and that he is then permitted four Amos in that direction only (See Tiferes Yisrael).

10)

(a)the Mishnah - permits two people whose Techumin inter-lap to place food in the common area and to eat, provided they are careful not to carry any food or articles (See Tos. Yom-Tov) from one of their individual domains to the other.

(b)If they are three people, and the T'chumin of the outer two inter-lap with the one in the middle, but not with each other - then the one in the middle may eat with them and they with him, but not with each other.

(c)Rebbi Shimon compares this to three courtyards one beside the other, where the outer two open into the R'shus ha'Rabim. If the outer two Chatzeiros made an Eiruv with the middle Chatzer, but not with each other - then, as in the previous case, the middle one may carry in the domains of the outer two, and they may carry in his domain, but not in each other's domain.

(d)The outer two do not forbid each other from carrying in the domain of the middle one - because they do not have an entree in each other's domain (See Tiferes Yisrael).

11)

(a)In the case of the three ...

1. ... travelers - the Chachamim concede to Rebbi Shimon that the middle one is permitted to eat with the two outer ones and they with him.

2. ... courtyards - they prohibit all three courtyards from carrying in the domain of any of the others ...

(b)... in case the residents from one of the outside courtyards come to carry from their own courtyard to the other outside courtyard, and nobody will remind them because there are many people involved, and those who live in the middle courtyard will not think of reminding whoever carries through their courtyard; whereas in the case of the three travelers, the middle one will remind the other two not to pass food or vessels from one domain to the other.

(c)The Halachah is - like Rebbi Shimon.

12)

(a)In a case where a traveler spots a tree or a wall that is within two thousand Amos from where he is, but who is too tired to continue walking, and before lying down to rest he declares 'Shevisasi Tachtav!', the Mishnah rules - 'Lo Amar K'lum!' ...

(b)... because he did not specify which four Amos he has designated as his central point.

(c)And he is only permitted to walk within his four Amos, which are not Koneh Shevisah on his behalf - since he did not intend them to (See Tos. Yom-Tov).

13)

(a)It would be valid however, even though he added nothing to his declaration - if the branches spanned less than eight Amos from one tip to the other, since then whichever side he might have had in mind incorporates a small section in the middle, which becomes his central point 'Mah Nafshach'.

(b)To enable him to walk further irrespective of the span of the branches he would need to say - that he is Koneh Shevisah by the trunk.

(c)He would then be permitted to walk - four thousand Amos, two thousand Amos up to the trunk and another two thousand Amos from the trunk (See Meleches Sh'lomoh),

14)

(a)If there was no tree or any other landmark, to enable him to walk another two thousand Amos, the traveler has to say - 'Shevisasi bi'Mekomi' (See Tos. Yom-Tov).

(b)The other case the Tana adds (even assuming that there was a tree at the end of two thousand Amos) is - where he wasnot an expert in Hilchos Eiruv (and did not know that he could fix an Eiruv in the distance).

(c)According to Rebbi Chanina ben Antignos, the two thousand Amos constitute a circle. The equivalent Din by the Arei Miklat (the cities of refuge) is - that one measures a square.

(d)The source of T'chumin is - the Pesukim by Arei Miklat (See Tos. Yom-Tov).

(e)Rebbi Chanina nevertheless rules that here they are round, from the word "Zeh" (in the Pasuk in Mas'ei "Zeh Yih'yeh lahem Migr'shei he'Arim"), from which he Darshens 'la'Zeh Atah Nosein Pe'os (i.e. corners), ve'I Atah Nosein Pe'os le'Shovsei Shabbos'.

15)

(a)The Chachamim say- that here too, the traveler has two thousand Amos in the shape of a square ...

(b)... giving him the extra corners.

(c)Their ruling is based on the same Pasuk in Mas'ei - which they Darshen as - "ka'Zeh Yih'yu Kol Shovsei Shabbos".

(d)The Rambam explains the expression 'keTivla Meruba'as' (as opposed to 'be'Rivu'a') - to mean that one only needs to measure an approximate square (the way people draw freehand), seeing as it is impossible to measure an exact square.

16)

(a)When Rebbi Meir says 've'Zu Hi she'Amru 'he'Ani Me'arev be'Raglav' - he means that it is specificlly in such a case, where the traveler did not have bread, rendering him a poor man, that the Chachamim permitted him to make an Eiruv on foot (See Tos. Yom-Tov).

(b)Consequently, a wealthy person who is not traveling is only permitted to make an Eiruv by placing bread.

(c)Rebbi Yehudah maintains that, on the contrary - the basic Din of Eiruv is on foot.

(d)According to him the Chachamim granted a special dispensation for a wealthy man who is unable to travel to the end of his current T'chum before Shabbos to send a Shali'ach with bread instead.

(e)The Halachah is - like Rebbi Yehudah.

17)

(a)Regarding someone who declares 'Shevisasi be'Makom P'loni', both Rebbi Meir and Rebbi Yehudah hold that only someone who is either poor or who is traveling and does not have bread with him (See Tos. Yom-Tov) is Koneh Shavisah.

(b)In addition - he must be able to arrive at his designated spot before Shabbos enters, even if it would mean running to get there (See Tos. Yom-Tov).

18)

(a)The Mishnah discusses someone who set out to place an Eiruv on behalf of the people of his city, and his friend stopped him and persuaded him to return home - because of the heat or the cold.

(b)Rebbi Yehudah says - that although he is permitted to walk two thousand Amos from the spot where he intended to place the Eiruv, the people of the city are not.

(c)He is permitted - because since he set out to place the Eiruv, he is like a poor man who said 'Shevisai be'Makom P'loni!', and he is Koneh Shevisah there (See Tos. Yom-Tov).

19)

(a)Rebbi Meir says that since he could have placed the Eiruv but didn't, 'Harei Hu Chamar Gamal' (See Tiferes Yisrael) - by which he means that he may only walk the two thousand Amos from the city to the location of the intended Eiruv, not even one Amah in the opposite direction (in case the Eiruv is effective), but not even one step beyond the Eiruv (in case it is not) ...

(b)... because Rebbi Meir is not certain whether he is considered a poor man, like Rebbi Yehudah explains, or whether, since he was able to place an Eiruv, he is not considered a poor man, in which case the Eiruv is invalid.

(c)The Halachah is - like Rebbi Yehudah.

20)

(a)The Tana Kama forbids someone who stepped one Amah outside his T'chum (i.e. beyond two thousand and four Amos) - to enter the town.

(b)He only allow him to walk - four Amos in all directions.

(c)The fact that the four Amos that he is allowed to walk overlaps the four Amos next to the city does not permit him to enter the city - because the Tana Kama does not consider the overlapping of the Techumin to be a factor with which one contends.

21)

(a)Rebbi Eliezer allows him to enter the town - if he is standing two Amos beyond his T'chum, but not three.

(b)The significance of the two Amos - lies in Rebbi's opinion earlier that a person who leaves the T'chum has two Amos in every direction (as we learned earlier in the Perek).

(c)Rebbi Eliezer disagrees with the Tana Kama - inasmuch as, according to him, we do contend with the overlapping of the Techumin.

(d)The Halachah is - like the Tana Kama (See also Tiferes Yisrael).

22)

(a)The Mishnah rules that a traveler who is one Amah short of the T'chum of the city - is not permitted to enter the city (See Tiferes Yisrael).

(b)Rebbi Shimon - permits him to enter even if he is fifteen Amos away from the city when Shabbos enters ...

(c)... because, due to a possible error in the measurement, the measurers actually place the sign for the T'chum some fifteen Amos within the T'chum (See also Tos. Yom-Tov.