City shaped like a bow (Eruvin 55a)

This morning I had a little disagreement on pshat in Rashi when he says how to measure the bow shaped city that has 4000 amos or more between then ends. I understood that it meant that each person gets 4000 amos from his house so if a guy in middle of the bow leaves from the end, he may only get a few amos. Basically it's as though each house is treated as it's own city so you only square off each house since the city can't be combined.

Others understood it to mean that it depends where you're counting from - basically this is an exception where we won't have a square shaped city. You'll count two thousand from the center and then 2000 from each end. I found that hard to believe that was what Rashi meant. It turned out that our disagreement was actually a machlokes between the Rashba and the Ritva in how to explain Rashi.

Kollel Iyun Hadaf summarizes all the opinions:

(a) RASHI (DH Pachos; 61a, DH Ir ha'Asuyah) writes that "each person measures the Techum from the entrance of his house." Rashi implies that one may walk only 2000 Amos from his house, even though he is still within 2000 Amos of the border of the city. Rashi understands that we ignore the city limits entirely when the city is shaped like a broad bow and we view the house as though it is in an uninhabited desert. (This is the understanding of the RASHBA and MAGID MISHNEH (Hilchos Shabbos 28:8) in Rashi's words.)

(b) The RITVA and RASHBA disagree with Rashi. They point out that in every case of a city, the entire area of the city is considered like one's four Amos with regard to the Shabbos Techum, and the 2000-Amah Techum is measured from the borders of the city. Similarly, for the people living in the bow-shaped city, when the Techum cannot be measured from the "bowstring" it is measured from the borders of the "bow" part of the city (i.e., from the place along the "bow" that is parallel to the person's house). The RITVA asserts that this is also the intention of Rashi -- we measure each person's Techum from the edge of the bow. For those living further inside the bow, we measure 2000 Amos from the point along the bow that is closest to them. (According to this understanding, Rashi mentions "each person's house" only to negate the following two opinions.)

(c) The ROSH cites the MAHARAM MI'ROTENBURG who maintains that the people in the bow may walk 2000 Amos in the direction of the bowstring, starting from the place where the two separate sides of the bow have not yet begun to spread apart from each other, and an imaginary bowstring of less than 4000 Amos can be drawn between the two ends of the bow.

(d) The TUR (OC 398) explains that those in the bow may walk 2000 Amos in the direction of the bowstring starting from a point 2000 Amos away from the bow.

(e) The Rashba quotes the RA'AVAD who points out that one who walks in the direction opposite that of the bowstring may walk not only 2000 Amos from the border of the city, but also 2000 Amos from an imaginary square that is circumscribed around the bow's bend of the city. (That is, this bow-shaped city is measured the same way the Techum of any city, whose borders are not straight lines, is measured. A square is circumscribed around the city, from which the Techum is then measured; see previous Insight.)

HALACHAH: The SHULCHAN ARUCH (OC 398:4) writes only that the Techum is measured from the "bow" part of the city ((b) above). The REMA adds that it is measured from where the bow widens to more than 4000 Amos ((c) above).

retraction? (Eruvin 43a)

This is a summary of the gemara in Eruvin 42b-43a courtesy of kollel iyun hadaf.

Question: All agree that the Halachah follows him [Rabban Gamliel] regarding a boat - what is the reason?
Answer #1 (Rabah): It is because he was Shoves within Mechitzos from before Shabbos;
Answer #2 (R. Zeira): It is because the boat constantly moves him out of his four Amos (he is like one who was forcibly taken by Nochrim out of his four Amos, he receives the four Amos in which they put him - this applies every time he steps, therefore the entire boat is permitted).
Question: What is the difference between these answers?
Answer #1: They argue about if the boat's walls were diminished [from 10 Tefachim - Rabah's reason no longer applies, R. Zeira's does];
Answer #2: They argue about one who jumped from one boat to another (Rabah forbids, for he was not Shoves within these Mechitzos).
Question: Why didn't R. Zeira answer like Rabah?
Answer: The walls of a boat are merely to keep the water out (they are not considered walls to make a boat like four Amos).
Question: Why didn't Rabah answer like R. Zeira?
Answer: All the Tana'im permit a moving boat [for R. Zeira's reason], they argue only about a stationary boat (R. Zeira's reason does not apply then. Tosfos - we retract from the two answers given above regarding the difference between Rabah and R. Zeira.)

When I went to the point by point summary I was happy to see that they quoted Tosafos because that's what I wanted to write about. Tosafos says that it must be that we're retracting because Rabba agrees with R' Zeira by mehaleches. R' Akiva agrees that if the ship is moving then you're allowed to move throughout the boat but he only argues by a standing ship then his reason must be mechitzos. Tosafos seems to assume that if R' Akiva agrees in a moving ship because of the walls then R' Gamliel must hold of that sevara also and therefore the gemara must be retracting the first two answers.

I don't think that it's muchrach to say as Tosafos does. It's true that Rabba agrees with R' Zeira that R' Akiva's reason is because the boat is moving but that doesn't necessarily mean that he's changing his explanation of R' Gamliel. He could be saying that is exactly the machlokes between the two. Rabban Gamliel says that the reason is because the mechitzos were there and R' Akiva says the reason is because the boat is moving. That means that R' Akiva could end up being more meikil. He would say that if the walls fall down or if someone jumped ship that you would still keep get 2000 amos but if the boat is stationary then you only get four amos. Rabban Gamliel would say just the opposite that if the boat is stationary you still get 2000 but if the walls fall down or you jump ship then you don't get them.

I haven't had a chance to look at the other rishonim but I suspect that someone must say it because pashut pshat in the gemara is that we're not being chozeir from what we said originally.

Carrying within 2000 amos (Eruvin 42a)

The gemara quotes a machlokes amoraim in the case of someone who camped out in a large valley with no walls and on Shabbos some people built a wall around the entire valley. He can definitely only walk 2000 amos from where he started but the question is if he can carry. Normally you can carry even if the mechitzos were only put up on Shabbos.
Rav Nachman in the name of Shmuel: This is no different in a regular case so he can carry throughout the valley "al yedei zerika" even though he can only walk 2000 amos.
Rashi: He can carry regularly in the first 2000 amos and he can only throw beyond the 2000 amos because he's not allowed to walk there.
Tosafos: He can't carry anywhere in the bika because it's open l'makom h'asur lo but he can throw throughout the bika even beyond 2000.
Rav Huna:He can only carry the 4 amos. The fence doesn't help because we're afraid that he might follow the object he's throwing. He can't even throw within the first 2000 amos because it's open l'makom h'asur lo.

Then the gemara quotes Rav Chiya bar Rav (might have been named after his great uncle) who says that you can carry within 2000 amos. The gemara then questions that doesn't follow either opinion so how could he say that. The gemara's question is a little difficult to understand because why should he be forced into agreeing with one of the other opinions. He was a contemporary. They all lived the generation after Rav and Shmuel so he should have been able to argue. Rashi therefore explains the gemara's question wasn't that he can't argue but that there is no svara to split the psak. He seems to take a compromise shita which is very difficult to understand.

According to Tosafos above, I think that it's clear that Rav Chiya bar Rav's shita as written originally doesn't make sense. You can never do more within the first 2000 than you can do beyond because there is no heker separating them. Rav Nachman holds you can throw throughout and Rav Huna says you can't throw anywhere. It doesn't make sense to suggest that you can carry only 2000 amos.

However, according to Rashi it's a little harder to understand why the gemara finds Rav Chiya bar Rav's shita impossible to understand. All he's saying is that you can carry within the first 2000 amos but not beyond. That's not so different than Rav Nachman who basically says that but he says you can throw beyond that point. Obviously the gemara assumes that's not considered a makom asur since you can throw there. If you can't even throw there then there's no way you should be allowed to carry within 2000 amos. I can understand the svara but Rav Chiya's opinion as written doesn't seem so crazy either. I would think it would be possible that he believes that really m'ikar hadin you could carry throughout the valley. The only reason you can't carry past there is because you might walk there and we're not going to forbid you from carrying within 2000 just because of that gezeira. I guess the gemara doesn't like that svara - if you can't carry (or throw) there for any reason then that's considered a makom asur.

Kasha (Eruvin 40b)

The gemara on daf 40a asks if we mention Rosh Chodesh in davening on Rosh Hashana. The gemara brings a braisa as proof. The gemara going on to daf 40b brings a proof from a braisa that you don't mention Rosh Chodesh because Beis Shammai says that you only make 10 brachos on Rosh Hashana and not 11 so you see that Rosh Chodesh doesn't get its own bracha. The gemara concludes the proof and says "kasha." Then five lines later the gemara asks what the conclusion is - do we or do we not mention Rosh Chodesh. This question seems strange because we just answered it a few lines earlier.

I think that the simple answer is like the Rosh says on the gemara in Shabbos 22b (the Rashash on our gemara pointed me there) that even though the gemara says kasha that's not irrefutable proof. It just means that it seems to be a question. Now the gemara wants to know if that proof is accepted l'halacha. This fits in with the explanation (I think it's the Rashbam in Baba Basra) that tyuvta means that it's a real proof but kasha just means that we don't know the answer. The Ritva explains why it's not a clear proof. All this braisa proves is that you don't mention Rosh Chodesh in the bracha but it does not proof that it doesn't get any mention in shmone esrei.

However, this explanation doesn't work with Rashi in d"h kasha on our gemara because he says that "shma mina" from the question that the halacha is that you don't mention shma. So if Rashi's right then why does the gemara ask what the halacha is. The Rashash explains that the next line after kasha is "kollel atzmo tanai hi" - the entire concept of kollel (from that braisa) is actually a machlokes tanaim. The gemara's point is that the entire braisa which is clear proof (acc. to Rashi) is only a daas yachid because it's assuming kollel but in reality others argue. So after the gemara says that it goes back and says that the proof isn't a proof according to everyone so then what is the halacha.

2 braisos vs. 1 mishna (Eruvin 37a)

On 36b Rav said that our mishna is wrong because Ayo's braisa disagrees. The gemara asks why he prefers Ayo to our mishna and answers because he has another braisa that supports Ayo. It still seems like 2 braisos vs. 1 mishna. We say later in the gemara that in a case of 2 vs. 1 we'd prefer to change the 1 than the 2 but here it's a mishna on the other side so I would've thought that the Mishna should win. I saw that Rabbi Bechhofer discusses this.

Teshuvos Kol Mevaser (2:46) critiques the work of a Rabbi in Vienna who put out a new edition of the Tosefta to Bava Kamma.

In the Introduction, the author cites our Gemara as an example of a tendency that Rav had to give precedence to a Tosefta over a Mishnah — since that is evidently what Rav is doing here. The author also cited Yevamos 83a, where Rav seems to even give precedence to a "non-Tosefta" Baraisa over a Mishnah. [Were this to be true, perhaps it could be seen as an extension of the concept of Rav Tanna u'Palig — Rav had the status of a Tanna, and therefore was entitled to dispute them (see Eruvin 50b).]

Kol Mevaser, however, rejects both examples.

In the first place, the Baraisa in Yevamos is a Tosefta – in the second chapter of Tosefta Bikkurim).

Moreover, Ido's Baraisa here is not a Tosefta!

Rather, states Kol Mevaser, it is only when there are two Baraisos that contradict a Mishnah — as is the case in our Gemara (see Tosafos to Yoma 54b d.h. Mai Shnah who define this principle; see also there that it is uniquely Rav's, and that others do not necessarily agree) — or a case in which there is some unique reason to prefer the Baraisa (as is the case in Yevamos 83b) that Rav gives the Baraisa precedence.

After reading his post, it struck me that it makes some sense that Rav would be the one to give precedence to a braisa over a mishna because Rav was Rabbi Hiyya's nephew (see the bottom of Moed Kattan 20a) and he compiled many of the braisos. We know that Rav was also a talmid of Rebbe but he doesn't give the mishnayos absolute credence over the braisos because of his relationship with Rabbi Hiyya.

2003 amos away (Eruvin 35a)

The gemara says that if the eruv rolled three amos after you had placed it 2000 amos away it's valid. What happens if l'chatchila you put it 2003 amos away? I wanted to do some research on that because I could hear both sides but I haven't had time. If I have time later I'll look around. In the meantime I wanted to know if anyone had heard anything.

pachos pachos m'daled amos (Eruvin 34a)

I just learned today's daf with Rashi but there were a couple of points on which I was confused.

1. At the beginning of the gemara Rashi says that even if you have to go through reshus harabim to get your eruv to your makom shevisa that's OK since you could do that bein hashemashos by carrying less than 4 amos at a time. Then at the bottom of daf 34a, he says in his second pshat when explaining the gemara which says that if you lean the shovach or migdal over it will be more than four amos away that the problem is that it's more than 4 amos in the reshus harabim. Doesn't that contradict what he said earlier? The Maharam answers that our imagination can only run so far. In other words, we can allow you to say that you could get it bein hashemashos if you carry less than four amos at a time and we can also allow you to say that you could get it if you lean the shovach or migdal over but we can't allow you to say both of them at the same time. That requires way too much pretending to allow the eruv. (I just checked the insights to the daf and they quote the same Maharam in different words and also have more to explain Rashi's pshat)

2. The first thing that bothered me about the case of the window and the rope is what changed between the hava amina and the maskana - didn't the gemara think that it's likely the guy didn't have the rope with him? Tosafos asks another question: Why all of a sudden here did the gemara introduce this idea? Why couldn't this have been possible in the case of the tree from daf 33? Tosafos answers that just isn't common so the gemara didn't even entertain the possibility. This would answer my first question - the gemara assumed that most people who are on top of cabinets next to walls have ropes with them (are you going to argue with that?) but the gemara answers that's not true. He also suggests another answer that since we're already saying hoil here we ask this question but in reality we could have asked it earlier.

Eruvin 33B

At the end of daf33, R' Yirmiya says that someone who's shevisa is in the Reshus Harabim at the foot of a tree and who's Eruv is in the basket attached to the tree above ten tefachim, the Eruv is valid since he can lower the basket below ten tefachim it is considered accesible Bein Hashmashos. Rav bar Sheva asks from an Eruv placed on Erev Yom Tov. Since a person can transport the Eruv from his house to his Makom Shevisah during Bein Hashmashos of Erev Y"T, why does the Mishna require him to actually place it in his Makom shevisa, according to R' Yirmiya the fact that he can transport it Bein Hashmashom to his Makom Shevisa should suffice to deem the Eruv accessible, and, therefore valid.

Why does the Gemarah feel that R' Yirmiya is more exposed to such a question than the original case of our Mishna (32B) which allowed an Eruv in a Reshus Harabim placed four+ Amos along the tree from your Makom Shevisa at the foot of the tree. In that case (as explained in accordance with Rava) the Eruv was valid since during Bein Hashmashos he can take the Eruv less than four amos at a time through the Reshus Harabim to his Makom Shevisa it was considered accessible Bein Hashmashos. Can't you ask just as well on the original case of the Mishna, that according to its logic, on Eruv Y"T it shouldn't be necessary to transport the Eruv to your Makom Shevisa, rather telepathically viewing your Eruv (which is sitting in your house) as transported to your Makom Shevisa should suffice?

In short, Why are we picking on R' Yirmiya?

(In Baba Basra R' Yirmiya was expelled from the B"M for asking about a bird who had one foot on one side of the line and one foot on the other. Maybe the Gemarah was telling R' Yirmiya to be careful, his P'Shat is crossing the line!-feel free to omit this comment)

Truma for a Yisrael (Eruvin 31a)

The Mishna on 31a says that a kohen can use truma for an eruv. The mishna though on daf 26b quotes that as a machlokes. The tanna kama says that even a Yisrael could use truma. Only Sumchus disagrees. This appears then to be a stam mishna like Sumchus - machlokes v'achar kach stam - implying that we should pasken like Sumchus. We don't and the Shiltei Giborim says that our Mishna doesn't mean that only a Kohen can use truma it's just using that as an example because they're the ones most likely to have truma.

Also, the mishna on 26b quotes another machlokes between an anonymous tanna (we'll call it Rabonnon) and R' Yehuda about a kikar in a beis hakvaros for a Kohen. The Rabonnon say that only if the kikar is in a beis hapras can a Kohen use it for his eruv but R' Yehuda says that even if it's in a beis hakvaros he can use it because it's still possible for the Kohen to get there. Rashi on daf 30b all the way at the bottom says that they both hold like Sumchus that it must be edible for that person and the only question is what's considered accesible. The top Tosafos on 27a argues with Rashi and says that the Rabonnon may really agree with the Tanna Kamma in the reisha that it doesn't have to be edible for that person. They say though that it does have to be accessible - because of a different rule of "hu b'makom echad v'eiruvo b'makom acheir."

Apples for an eruv (Eruvin 29a)

Rava challenged his student who asked how many apples you need for an eruv by asking him back how you could use apples for an eruv at all. What was Rava talking about, why shouldn't you be able to use apples for an eruv? The Yosef Daas section of the kollel iyun hadaf site quotes three answers to this question (I saw the Artscroll in the footnotes also quotes the same three answers):
1. Rava knew you could but he was just challenging the student to find a proof (from Tos on 27)
2. The question wasn't about regular apples but about wild apples that aren't normally eaten (quoted in the Rashba)
3. Rava held that you can't use things that aren't normally eaten as part of a meal for eruv. So you could use vegetables, meat, breat, and even salad dressing but not fruit (the answer the Rashba likes).

On a related topic I have a question on today's daf but I couldn't find anyone who discusses it leading me to believe that I'm just misunderstanding something. The gemara says that Rav said "v'chein l'eruv" on some tannaic statement about maaser ani. Rashi explains the gemara's question that the mishna and the braisa don't disagree with each other at all so what's the difference on which one we put the statement. I don't understand that. It seems like there is a machlokes. The braisa says that the shiur for peaches is 5, for esrog is 1 etc. and the mishna says the shiur for all fruit is the amount to sell and buy food for two meals. Are we saying that's the same shiur? Doesn't sound like it.

klal or rebuy (Eruvin 27b-28a)

The gemara quotes the pasuk by maaser sheni that has a general statement followed by a limitation followed by another general statement. There is a four way machlokes tanaim what exactly should be included by that.
R' Yehuda Ben Gadish - you can buy anything besides salt and water.
R' Eliezer - you can buy anything besides salt and water and fish water
Braisa 1 - you also can't buy fish
Braisa 2 - you also can't buy birds

The last two shitos learn Klal prat u'klal (KPK) as opposed to the first two who learn ribuy miut ribuy (RMR). RMR is always much more inclusive than KPK. It assumes that you should include everything except the most basic thing that is completely dissimilar to the miut. There are two different ways to learn KPK that the gemara discusses. One is that the second klal is the main one so you start with PK which means that it's israbu lahu kol mili - it includes everything. Then the first klal comes and limits that. It limits it more than if you would learn RMR but not as much as if the other way of looking at KPK. The other way is that you look at the first klal as being the main one which means that you really have a KP which is ein b'klal ela ma sheb'prat and then the second klal can expand it but it's not going to expand it as much as the first way.

That's basically a summary of the gemara and it explains the machlokes between the last three shitos. Just to summarize:

RYBG and R' Eliezer - Ribuy miut ribuy - very, very expansive to include almost everything
Braisa 1 - klal prat uklal but start with prat uklal - somewhat expansive
Braisa 2 - klal prat uklal but start with klal u'prat - much more limiting

The only question that remains is what the source of the machlokes is between RYBG and R"E. It seems that RYBG should be correct. RMR should include everything except the bare minimum so why does R"E also exclude fish water? The fact that the gemara doesn't explain it makes me think that it's not a general machlokes but just a basic machlokes related specifically to this case. I think that the machlokes is either that R"E says that the exclusion is saltwater and if you have clear fish water that is no different than regular saltwater. RYBG maintains that if it's fish water then that's very different than just salt mixed with water. Another possible explanation is that R"E says that salt and water were never included in the original ribuy b/c they're not mazon. The ribuy only includes mazon so the miut has to exclude something that was initially included so he says that is the fish water. RYBG must hold that it doesn't have to be "mazon" to be included in the ribuy - just has to be food. (Before posting this, I just checked the Ritva and he seems to say like my second explanation which I like better also.)

Dveila Keilis (Eruvin 27b)

The gemara says that had the pasuk about maaser sheni only said shechar we would have thought that it was coming to include dveila keilis (intoxicating dates from Keilis). We already know the klal, prat u'klal includes all food so why would would we have thought the extra limud includes these dates? Why wouldn't they be included?

Tosafos (in the middle of d"h hava) suggests that we're talking about watered down dates. It's more likely to be included than temed because the water is really mixed in but you still might have thought that it wasn't included like other foods. The Ritva has another answer. He says that these dates are inferior and aren't good for you so they're not normally eaten. You might have thought that they weren't considered like other foods and you couldn't redeem your maaser sheni onto them. (The Ritva has a a long, thorough explanation of our whole gemara. I didn't go through the whole thing but it did seem good.)