(Permission is granted to print and redistribute this material
as long as this header and the footer at the end are included.)


prepared by Rabbi Eliezer Chrysler
Kollel Iyun Hadaf, Jerusalem

Previous daf

Eruvin 4

ERUVIN 4 - dedicated to the memory of Sarah Dvosya bas Rav Mordechai (Feldman) of Milwaukee by her children.



(a) No! Rava is not saying that the Amos of a Sucah, a Mavoy and of Kil'ayim are the same. According to him, the Amos of a Sucah and a Mavoy consist of six tight Tefachim, and that of Kil'ayim, of six loose Tefachim - both Lechumra (like Abaye).

(b) Abaye tries to establish the Beraisa: 'Kol Amos she'Amru Chachamim be'Amah bas Shishah, u'Vilevad she'Lo Yehu Mechuvanos' - by Amos of Kil'ayim exclusively.

(c) This answer however, is unacceptable - because Raban Shimon ben Gamliel goes on to say 'Kol Amos she'Amru Chachamim be'Kil'ayim, be'Amah bas Shishah, u'Vilevad she'Lo Yihyu Metzumtamos'; from which we can deduce that the Tana Kama is speaking about *all* Amos (i.e. those of Sucah and Mavoy, too).

(d) Abaye answers - that seeing as Raban Shimon ben Gamliel voices his opinion, he follows the opinion of Raban Shimon ben Gamliel.

(a) According to Rava, Raban Shimon ben Gamliel's main Chidush - is that the Amah of Kil'ayim should not be measured tightly, and the reason that he adds 'be'Amah bas Shishah' - is not to exclude the Amos of Sucah and Mavuy, but to exclude the Amah of the Yesod of the Mizbei'ach, and that of the Sovev (the base and the ledge around which the Kohanim could walk, respectively), which consisted of *five* Tefachim, rather than *six*.

(b) "ve'Eleh Midos ha'Mizbei'ach be'Amos, Amah, Amah ve'Tefach, ve'Cheik ha'Amah", according to Rashi's final explanation, means that, even though all the measurements of the Mizbei'ach consist of one Amah (of five Tefachim) plus a Tefach, the Amah of the Yesod will consist of just an Amah.

(c) It was the height of the Yesod that was a small Amah; the width was a regular Amah.

(a) Both the Amah width and the Amah height of the four Keranos - consisted of small (five-Tefachim) Amos.

(b) A Zeres is half an Amah. Consequently, when the Pasuk gives the width of the Keranos as being a Zeres - it is referring to the measurement of the Keranos from the middle, one Zeres in each direction.

4) Also the Amah square of the Mizbei'ach ha'Zahav (the small incense-Altar) consisted of a small Amah of five Tefachim.


1. If someone enters a house which has Tzara'as, holding clothes or rings in his hands, he and the clothes become Tamei immediately. Not so the clothes and the ornaments that he is wearing - they only become Tamei if he waits in the house the amount of time it would take to eat an Achilas Peras (four egg-volumes) of wheat-bread with condiments, whilst he is leaning (each of these details diminishes the time of eating).
2. The bone of a corpse is Metamei - by touching and by carrying (but not by Ohel) if it is the size of a barley.
3. The Shiur of the pits and the skin of grapes that a Nazir needs to eat in order to be Chayav (Malkus) - is a Revi'is (of a Lug = one and a half egg- volumes) of wine (which is thicker than water, and therefore has more surface tension than water.
4. The Shiur for carrying on Shabbos as regards food is that of a 'ki'Gerogeres' (a dried fig).
5. Wooden vessels which break, no longer receive Tum'ah. People still tend to use a vessel with a hole up to the size of a pomegranate, for which reason it will still receive Tum'ah. Once it is the size of a pomegranate however, the owner throws it away, and it no longer receives Tum'ah. (These Dinim are confined to the vessels of private people, not to vessels that are sold in shops, where they tend to discard all broken vessels, however small the hole).
6. The Shiur of most things is a Kezayis. The list includes Cheilev, blood, Nosar and Pigul.
7. The Shiur for which one is Chayav Kares on Yom Kipur is that of a Koseves (a date).
(b) In fact, the Shiurim are 'Halachah le'Moshe mi'Sinai', but the Rabbanan found support for them in this Pasuk (not that we actually learn the Shiurim from there).



(a) We learn from ...
1. ... "ve'Rachatz es Kol *Besaro"* - that nothing may interrupt between the water and the skin (known as a Chatzitzah) when one Tovels.
2. ... "ba'Mayim" - that one must Tovel in a collection of water (a Mikveh), though not necessarily in spring water.
3. ... "ve'Rachatz es *Kol Besaro*" - that there must be sufficient water in the Mikveh for an average person to Tovel (one Amah by one Amah by three Amos = forty Sa'ah).
4. ... "*es* Kol Besaro" - that knotted hair is also a Chatzitzah (as will be explained immediately).
(b) Rabah bar Rav Huna said - that one knotted hair is a Chatzitzah, three is not, whereas two was a Safek by him.

(c) When Rav said that Chatzitzin are 'Halachah le'Moshe mi'Sinai' - he was referring to Rav Yitzchak, who said (with referrence to hair - see Tosfos Dh 'Devar Torah') 'Devar Torah (i.e. ' Halachah le'Moshe mi'Sinai') Rubo u'Makpid Alav, Chotzetz, ve'she'Eino Makpid Alav, Eino Chotzetz'.

(d) The Rabbanan decreed - by Rubo she'Eino Makpid and by Mi'uto ha'Makpid.

(e) The Rabbanan did not decree on Mi'uto she'Eino Makpid because of Mi'uto ha'Makpid or because of Rubo she'Eino Makpid - because that would be a Gezeirah li'Gezeirah, which the Rabbanan do not usually do?

(a) Chazal have said that Hashem did not descend lower than ten Tefachim, from which we see that above ten Tefachim is considered a different Reshus. Now the Aron, from whose lid Hashem spoke to Moshe, was nine Tefachim high, which, together with the one Tefach of the lid, makes ten Tefachim. So we see that ten Tefachim constitutes a Mechitzah.

(b) Rav says that Mechitzin is Halachah etc. - according to the opinion of Rebbi Yehudah, in whose opinion the Amos of the Aron (and of all the holy vessels) were Amos of *five* Tefachim, and not of *six* (which means that the Aron was not ten Tefachim tall, but eight and a half). Consequently, Mechutzin can indeed be 'Halachah le'Moshe mi'Sinai'.

(c) According to Rebbi Meir (who learns Mechitzin from the Aron), the Halachah by Mechitzin was said by 'Gud', 'Levud' and 'Dofen Akumah': 'Gud' means that we sometimes stretch a wall upwards ('Gud Acheis Mechitzasah') or downwards ('Gud Asek Mechitzasah') - as if it reached the ceiling or the floor, even though, in reality, it does *not*; 'Levud' means that whenever there is a space of less than three Tefachim, we extend the wall to the end as if it was filled in; 'Dofen Akumah', which is confined strictly to the Dinim of Sucah, means that we permit Pasul Sechach between the Sechach and the wall of the Sucah as if the wall of the Sucah was bent (which is no reason to invalidate the Sucah).

(a) In the case of a Koreh which is higher than twenty Amos, one could of course, simply lower the Koreh. However, it would probably be easier to raise the level of the ground, by piling up earth across the width of the Mavuy (which is the option discussed by the Gemara).

(b) According to Abaye, one would need to fill in earth for four Tefachim along the Mavuy.

(c) The Gemara initially explains that Rav Yosef permits carrying under the Koreh (because it is the *outer* edge of the Koreh which is considered to be extended to the ground). Consequently, one Tefach (the Tefach underneath the Koreh) will suffice; whereas Abaye forbids it (because, according to him , it is the *inner* edge that is considered to be extended) That is why four Tefachim (a significant measurement) is required.

(d) Abaye (in the first alternative answer) requires four Tefachim - because, according to him, a Koreh does not serve as a Heker, but as a Mechitzah. In fact, he too agrees that it is the *outer* edge that is 'extended'. However, a Mechitzah must serve a Reshus of at least four Tefachim, which is why he requires piling up the earth for a length of four Tefachim.

9) According to the Gemara's final interpretation of Abaye - Abaye agrees with Rav Yosef that a Koreh serves as a Heker, and that even a Heker from underneath ought to suffice. However, he decrees that one Tefach is not sufficient, because people might tread down the earth to a point where the Koreh will once again be more than twenty Amos high. And since one Tefach is not enough, he requires four Tefachim, which is considered a significant measurement in other places.

Next daf


For further information on
subscriptions, archives and sponsorships,
contact Kollel Iyun Hadaf,