1)

(a)The problem with using a heated knife to Shecht might is that - perhaps one burns the Si'manim, instead of cutting them.

(b)Rebbi Zeira Amar Shmuel nevertheless declares the Shechitah Kasher - because, in his opinion, the cut precedes the burn.

(c)He is not afraid that the side of the knife will touch the pipe before the majority has been cut - because as the knife cuts into the pipes, the sides part before the sides of the knife touch them (Chidudah Kodem le'Libunah).

2)

(a)The Mishnah in Nega'im discusses a Sh'chin and a Michvah. When the Tana gives the maximum time period as one week (as opposed to Se'eis and Sapachas, where the maximum time period is a fortnight), he means that - if, after one week no Simon Tum'ah has appeared (and the Sh'chin or the Michvah remain unchanged), the Kohen declares the Metzora Tahor.

(b)The two Simanim that render them Tamei are - two white hairs and the mark spreading.

(c)The Torah divides them into two Parshiyos - to teach us that half a G'ris (the size of a bean, which is the minimum Shi'ur for Tzara'as) of one, does not combine with half a G'ris of the other, to render the stricken person Tamei.

3)

(a)Besides a burn caused by fire, "Michvah" incorporates - anything that has been heated directly by fire (such as a burning coal, hot ashes or boiling lime).

(b)And the definition of a Sh'chin (which is a derivative of Shechunah [meaning hot]) is - anything that heats the skin that has not been heated directly by fire (such as a piece of wood or a stone [that strikes a person], hot peat made of olive peels, or Chamei Teverya [the hot-springs of Teverya]).

(c)When the Beraisa concludes ...

1. ... in the Seifa u've'Chol Davar ha'Ba Machmas ha'Or, it comes to include - Chamei ha'Or (such as water that has been boiled on the stove).

2. ... in the Reisha u've'Chol Davar she'Lo Ba Machmas ha'Or, it comes to include - lead that was hot from the time it was mined.

(d)Another Beraisa defines Tzara'as on a location where a burn follows a boil, or vice-versa as - whichever occurred last (since it negates whatever precedes it).

4)

(a)The question now arises as to the definition of Tzara'as on a location that was struck with a hot spit-rod, whether it is considered a Sh'chin or a Michvah. The She'eilah affects a case where - a Sh'chin of half a G'ris, say, is located immediately beside the location of the stroke (which is also the size of half a G'ris). If the force of the stroke precedes the burn, then it creates a Michvah, which will not combine with the Sh'chin; whereas if the burn came first, then the two half G'risin of Sh'chin will combine.

(b)We refute the proof from ...

1. ... Rebbi Zeira Amar Shmuel, who said Chidudah Kodem le'Libunah' (which is not a proof that the stroke precedes the burn) - because it may well be that a cut (due to its sharpness) precedes the burn, whereas a regular stroke does not.

2. ... the Beraisa Libein Sh'pud Ve'hikah bo, Nadun Mishum Michvas Eish for the same reason - since the Tana may well be speaking in a case where the stroke was delivered with the sharp end of the spit-rod, piercing the skin of the victim (which will not solve our She'eilah, as we just explained).

5)

(a)We learn from the Pasuk "Abeid Te'abdun es Kol ha'Mekomos" that - Meshamshei (vessels of) Avodah Zarah are Asur be'Hana'ah.

(b)Rav Nachman Amar Rabah bar Avuhah ...

1. ... permits Shechting with a knife of Avodah-Zarah - because Shechting a healthy animal is basically a Kilkul (since it negates its potential [triple] use for breeding, plowing and as food), and is not therefore considered a Hana'ah.

2. ... forbids cutting meat with it - because, once the animal has been Shechted, the meat stands to be cut into pieces, in which case, cuttng it, is considered Hana'ah.

(c)Rava maintains however, that one may ...

1. ... not Shecht with it - an animal that is very sick (whose sole use is therefore as food).

2. ... cut meat with it - if it has already been cut into pieces that are Chashuv (the thigh, the shoulder, the breast), in which case cutting it into smaller pieces will be considered Kilkul.

(d)To explain why the pieces of meat are not forbidden on account of the grease on the knife, we establish Rava's latter ruling - by a new knife that has never been used.

6)

(a)Rebbi Akiva and Rebbi Yishmael argue (in Avodah-Zarah) over - whether a new idol is forbidden or not.

(b)They both agree however that - a new vessel of Avodas Kochavim is permitted.

(c)The problem this creates with the way we just established Rava's statement is that - the knife ought then to be permitted even as regards Shechting an animal that is very sick.

(d)We answer that Rava may be speaking in a case where the knife was in fact, used for Avodah Zarah, but for cutting wood, and not meat. Alternatively, he may be speaking (even assuming that it was used for cutting meat) - where it was first Kashered in fire.

7)

(a)Rav says that if someone Shechts with a knife belonging to a Nochri, the neck requires peeling. According to Rabah bar bar Chanah - it will suffice to wash it.

(b)Initially, we establish their Machlokes as to - whether the Beis ha'Shechitah is hot (the heat of the Beis ha'Shechitah causes it to absorb the grease on the knife [Rav]) or cold (Rabah bar bar Chanah).

(c)We conclude however, that even if both opinions agree that the Beis ha'Shechitah is ...

1. ... hot, Rabah bar bar Chanah will require only washing - because, since the Si'manim are busy exuding blood, they will not absorb any grease.

2. ... cold Rav will nevertheless require the neck to be peeled - because the pressure of the knife causes the neck to absorb the grease.

(d)According to Rabah bar bar Chanah, the Beis ha'Shechitah needs washing - because of the grease on the knife, which sticks to the neck of the slaughtered animal.

8)

(a)We can extrapolate from the Lashon ha'Shochet be'Sakin shel Nochri - that - it is only Bedi'eved that one may Shecht with the knife of a Nochri, but not Lechatchilah.

(b)If one did Shecht with it - the Beis ha'Shechitah will require peeling (like Rav), since in a matter concerning a d'Oraysa, we follow the stricter opinion.

9)

(a)If the animal that one Shechted turns out to be a T'reifah, Rav Acha and Ravina argue over what to do with the knife. One of them says that it requires Hag'alah in boiling water. The other one says that - it must be washed in cold water.

(b)The one holds Hag'alah in boiling water - because the knife absorbs some of the fat of the T'reifah animal; the other washing in cold water - because he holds that the Beis ha'Shechitah is cold, and (in spite of the pressure of the knife) does not absorb any fat.

(c)We conclude that - it will suffice to wash it in cold water.

(d)We rule leniently here - because the knife, which is Kasher to begin with, is hard and will only absorb when there is heat, whereas in the previous case (with regard to the knife of a Nochri) - the knife is not Kasher to begin with, and the Beis ha'Shechitah, which is soft, absorbs easily.

10)

(a)The knife will not even require washing in cold water - if there is a piece of worn out curtain (not a fresh, soft cloth) available with which to wipe the knife clean.

(b)The one who requires Hag'alah is not concerned that (by the Shechitah of a Kasher animal), the knife has absorbed ...

1. ... blood - because a hard knife will absorb fat and grease, but not blood, which is liquid.

2. ... Eiver min ha'Chai - because it only absorbs when the Beis ha'Shechitah becomes hot, and that takes place only after the Shechitah, when it is no longer Eiver min ha'Chai.

11)

(a)Rav Yehudah Amar Rav requires a Shochet to have three knives - one for Shechitah, one for cutting meat and one for cutting Chalavim.

(b)He cuts Chalavim - to sell in the market.

(c)He cannot use the same knife to cut meat and to Shecht - because it is likely to become defected, and should he then forget to examine it, his Shechitah will be Pasul without him even being aware of it.

12)

(a)We ask why the Shochet cannot use the same knife to cut both meat and Chalavim - in which case, he would have to take care to cut the meat first, and then, after cutting the Chalavim, to wipe the knife clean before cutting meat with it again (see also Tosfos DH 'Ve'liskin Chada').

(b)We answer that we are afraid that he will forget and cut the Chalavim first. Despite the fact that he can just as easily forget which knife is which, the advantage of having one knife for meat and one for Chalavim is that - having two knives will prompt him to make a Si'man to differentiate between them.

(c)Rav Yehudah Amar Rav also requires two separate dishes for washing the meat and the Chalavim, because we are afraid that he will forget and wash the meat after the Chalavim, in which case (despite the fact that the water is cold) - some fat from the Chalavim that inevitably mixes in the water, will stick to the surface of the meat.

13)

(a)Ameimar citing Rav Papa forbids placing the flanks with the Cheilev of the kidneys on top of a piece of meat which is lying on a board - because the heat generated by the weight (see also Tosfos DH 'Lo Lischof') will cause the meat to absorb some of the Cheilev.

(b)The flanks themselves, on the other hand, do not become forbidden because of the Cheilev on top of which they are lying - because a thick membrane separates them.

(c)That membrane - must be removed from the flanks, because, due to the Cheilev that is mixed in it, it may not be eaten.

(d)We prohibit placing the flanks on top of the piece of meat, in spite of the membrane that covers all Cheilev - because that membrane, which is thin, becomes ruptured through the handling of the butcher, and will not therefore prevent the meat from absorbing some of the Cheilev.