1)

(a)Tana'im argue over whether food that is prepared in a non-Kashered utensil belonging of a Nochri on the following day, is permitted or not. One Tana permits it - because it is 'Nosen Ta'am li'Fegam'.

(b)And when the Torah requires Hag'alah - it is in order to use it on the same day.

(c)And utensils obtained from a Nochri are nevertheless not permitted Lechatchilah after the first day - because the Chachamim issued a decree (in case one comes to use them on the first day).

2)

(a)The second Tana nevertheless forbids the food even Bedi'eved, in spite of the Heter of 'Nosen Ta'am li'Fegam' - since inevitably, the food is slightly spoiled already on the first day (as we learned earlier in the Perek), yet the Torah requires the vessels to be Kashered.

(b)The Mishnah in Zevachim rules that - a spit-rod and a grill of Kodshim require Hag'alah in boiling water.

(c)When Rav Amram queried this from our Mishnah, which requires Libun (in fire) - Rav Sheishes differentiated between Chulin, which absorbed what is forbidden ('Isura Bal'a') and Kodshim, which absorbed what is permitted ('Heteira Bala').

3)

(a)Rabah disagreed with Rav Sheishes' distinction - since even if Kodshim is Heter when it is absorbed, by the time it is exuded, it has already become Asur (because of Nosar) and is therefore considered to be 'Isura Bala'.

(b)So he interpreted the 'Hag'alah' in Zevachim as - Sh'tifah and Hadachah (rinsing and washing), which is a 'Gezeiras ha'Kasuv' ...

(c)... that is required over and above the Libun that it requires anyway.

(d)Abaye objected to Rabah's interpretation of Hag'alah - inasmuch as Sh'tifah and Hadachah implies only cold water, whereas Hag'alah implies hot water.

4)

(a)To resolve the discrepancy, Abaye therefore explained 'Yagid alav Re'o' - Chulin requires Libun, as well as Hag'alah (which we learn from Kodshim), and Kodshim requires Hag'alah, as well as Libun (which we learn from Chulin).

(b)Kodshim utensils still require Sh'tifah ve'Hadachah - since they are based on a 'Gezeiras ha'Kasuv', irrespective of whatever else is done to them.

(c)Rava's objected to Abaye's explanation - in that at least one of the Mishnahs ought then to have mentioned both Libun and Hag'alah, allowing us to learn from it, that just as both methods are required there, so too, by the other one.

5)

(a)So Rava cited Rav Nachman Amar Rabah bar Avuhah to explain the Mishnah in Zevachim. When Rav Nachman said 'Kol Yom ve'Yom Na'aseh Gi'ul la'Chavero', he meant that - by the second day, when one cooks again in the utensil, whatever is absorbed in the walls of the vessel has become 'Nosen Ta'am li'Fegam' (before it has had a chance to become Nosar).

(b)We agree with Rav Nachman with regard to the Korban Shelamim - for which the Torah allows two days to eat (and which has not therefore become Nosar by the second day). We query him however, from the Chatas - for which one has only day to eat (and which therefore becomes Nosar before the food becomes 'Nosen Ta'am li'Fegam').

(c)We can circumvent this problem however - by cooking the chest and the right calf of a Shelamim in the pot in which the Chatas was cooked that day, and by then cooking another Shelamim on the next day, before the initial Shelamim has become Nosar (See Ritva).

(d)The (unanswerable) problem with this is that - if that is so, why do the Kodshim pots require Hag'alah at all?

6)

(a)To explain the difference between Kodshim and Chulin, Rav Papa explains 'Hai Karid, Hai Lo Karid', by which he means that - even though by the time the pot exudes Kodshim, it has become Asur (as we explained), nevertheless, Hag'alah will suffice, because, due to the fact that the utensils are in constant use, the Isur does not get a chance to penetrate as deeply as Chulin ones (which is why they require Libun).

(b)Rav Ashi accepts Rav Sheishes' initial answer (which considers Kodshim 'Heteira Bala'), and he refutes Rabah's objection ('Ki ka'Palit, Isura ka'Palit') on the grounds that - the Isur, which was invisible from the very first moment, is therefore weak, so we consider it 'Heteira Bala'.

7)

(a)Rav ...

1. ... Mani defines the Shi'ur of Libun as - until one layer has been removed.

2. ... Huna explains Hag'alah - as placing the small pot (that requires Kashering) inside a large one (containing boiling water), so that the water covers it.

(b)According to Rav Ukva (or Rav Akavya), one makes Hag'alah on a large pot - by forming a rim of dough around its top outside edge and filling the pot itself to its very top with water.

(c)When Rava heard this, he exclaimed that only Rav Ukva, who was very wise, would have made such a statement - because it is based on the principle 'ke'Bol'o Kach Polto' (because the top surface of the pot absorbed splashing drops, and that's the way it is now being Kashered).

(d)The rim of dough around the edge is necessary - to ensure that drops splash everywhere. Otherwise, by boiling up water once, the chances are that parts of the top which absorbed 'T'reif', will not be affected by the drops this time.

8)

(a)Rav Ukva bar Chama rules that after having filed a knife - one has to stick it in hard earth ten times.

(b)Rav Huna b'rei de'Rav Yehoshua - requires virgin soil to be used for this procedure.

(c)If, as we explained, 'Shafah' in our Mishnah means 'files in a grindstone', the current Halachah seems rather excessive. Others therefore explain 'Shafah' to mean that - the knife has to be wiped clean, using a rough woolen cloth.

(d)Rav Kahana (supported by a Beraisa) qualifies the above ruling - by precluding knives with holes or grooves from this procedure (because they may contain fat which will not be removed).

9)

(a)Rav Huna b'rei de'Rav Yehoshua qualifies this concession still further. He restricts the use of this method of Kashering knives - to where they have been used for cutting cold foods, but not hot ones.

(b)When an Esrog was brought before Shavur Malka (King of Persia), he first cut himself a piece - and one for Bati bar Tuvi, but stuck the knife in the ground ten times before cutting a piece to give to Rav Yehudah.

(c)When Bati bar Tuvi asked him whether he thought that Rav Yehudah was a Yisrael and he was not, he replied that - he knew Rav Yehudah to be a devout Jew who would not eat anything that was forbidden, but he did not know whether the same could be said about him.

(d)In the second answer, he (Shavur Malka) reminded him of what had happened the night before - when he had accepted the Nochri woman that his host offered him for the night (as they tended to offer all their guests), whereas Rav Yehudah had declined the offer.