1)

(a)The Shi'ur of most Isurim to do with food is a k'Zayis. The Shi'ur of Tum'as Ochlin however, is a k'Beitzah - because the Torah in Shemini uses the unusual Lashon of "mi'Kol ha'Ochel Asher Ye'achel".

(b)Rebbi Elazar initially interprets this to mean 'food that comes from food' (i.e. an egg, that comes from a chicken). He explains like this because of the precedent by Yom Kippur, where we also learn a new Shi'ur from the fact that the Torah changes from "Lo Sochlu" to "Te'anu es Nafshoseichem".

(c)If not for the precedent from Yom Kippur, we would have thought that "mi'Kol ha'Ochel Asher Ye'achel" is the regular way to write it, and we would not have made such a Derashah.

2)

(a)The Shi'ur of Tum'as Ochlin cannot be ...

1. ... a kid-goat (which is also food that comes from food) - because, since it still requires Shechitah, it is not yet considered food.

2. ... a Ben Peku'ah (a live baby animal that one finds inside its Shechted mother) - because it too, must first be killed.

3. ... the egg of a large bird called a Bar Yochni - because of the principle 'Tafasta Merubeh Lo Tafasta' (we always take on the minimum implication).

(b)We retract from Rebbi Elazar's original explanation - because who says that the Shi'ur should be a chicken's egg? Perhaps it is the egg of smaller bird!

(c)Rebbi Avahu himself finally learns the Shi'ur of a k'Beitzah by Tum'as Ochlin from the same Pasuk ("mi'Kol ha'Ochel Asher Ye'achel") - which he explains to mean food that can be eaten in one go, and Chazal have assessed that the maximum that the human throat can hold is a chicken's egg.

3)

(a)Rebbi Elazar obligates someone who eats Chelev nowadays to record how much he ate, because Beis-Din might add to the Shiurim. This cannot mean that if he ate less than a k'Zayis, he should record it, in case Beis-Din reduce the Shi'ur of a k'Zayis, for which he is now obligated to bring a Korban (even though, according to the original interpretation of the Shi'ur at the time when he ate the Chelev, he was not) - because a transgressor b'Shogeg, who would not have retracted at the time when he performed the sin, even if he had been aware of the sin, because for example, he would not have been Chayav anyway, is Patur from a Korban. So how can a later institution, render him Chayav.

(b)Had we understood Rebbi Elazar like that, we would have explained his words 'Shema ... Yarbeh b'Shiurin' - to mean that they may increase the amount of Korbanos that are brought because of the change of Shi'ur.

(c)What Rebbi Elazar really meant was that someone who ate an average size k'Zayis should record it - in case the Chachamim change the Shi'ur to a larger one, which will render him Patur, and, should he now bring a Chatas, he will be bringing Chulin to the Azarah.

4)

(a)Rebbi Yochanan said 'Shiurin v'Onshin Halachah l'Moshe mi'Sinai'. This statement cannot be correct the way it stands - because the punishments are written explicitly in the Torah, so how can they be Halachah l'Moshe mi'Sinai?

(b)What Rebbi Yochanan meant was 'Shiurin shel Onshin' - which are not written.

(c)According to Acherim in a Beraisa, it was Ya'avetz - alias Osniel ben Kenaz (Kalev ben Yefuneh's half brother, and Yehoshua's successor) who taught us the Shiurin. This does not mean that he initiated them, but that he reinstated them (with his Pilpul) after they had been forgotten.

5)

(a)Our Mishnah gives the Shi'ur for drinking on Yom Kippur as 'Melo Lugmav' (two cheeks-full) - which really means one cheek-full.

(b)The Tana writes 'Melo Lugmav' - because he is referring to an amount that is slightly more than one ordinary cheek-full, so that, when all the liquid is moved to one side of the mouth, it gives the impression of being two cheeks-full.

(c)In a Beraisa, Beis Shamai gives the Shi'ur as a Revi'is, Beis Hillel as a Melo Lugmav and Rebbi Yehudah quoting Rebbi Eliezer, as ki'Melo Lugmav. Beis Hillel too, means ki'Melo Lugmav, like we explained our Mishnah - only according to them, the Shi'ur is the amount that resembles two large cheeks-full; whereas according to Rebbi Yehudah quoting Rebbi Eliezer, it is two average cheeks-full.

(d)According to Rebbi Yehudah ben Beseirah - the Shi'ur on Yom Kippur is as much as one can swallow in one gulp.

6)

(a)The problem with saying that (with regard to the Shi'ur of drinking on Yom Kippur) Beis Shamai gives the Shi'ur of a Revi'is and Beis Hillel as a ki'Melo Lugmav - is that, in that case, Beis Shamai is more lenient than Beis Hillel, and it ought to have been included in Iduyos, together with all the other cases where Beis Shamai is more lenient than Beis Hillel!?

(b)The answer to this is that strange as may sound, the Tana'im are discussing a case of Og Melech ha'Bashan (which was what the questioner asked them). Consequently, Beis Hillel, who gives the Shi'ur as 'Melo Lugmav' - Og's Melo Lugmav, is the more lenient of the two.

7)

(a)That the Shi'ur for drink on Yom Kippur (a Melo Lugmav) differs from person to person - is perfectly natural; and as far as food is concerned, Chazal assessed that a Koseves ha'Gasah stills a person's hunger, irrespective of his size.

(b)It is an established fact that a Koseves ha'Gasah is sufficient to still the hunger of Og Melech ha'Bashan, just as it does for a small person.

(c)It is also a fact that a Koseves ha'Gasah of edible vine-sprouts stills someone's hunger more or less in the same way as the same Shi'ur of a juicy steak.

8)

(a)The time-limit within which one must eat ...

1. ... a k'Zayis of forbidden foods in order to be Chayav - is a 'k'Dei Achilas Pras' (four egg-volumes)

2. ... a Koseves ha'Gasah on Yom Kippur - a 'k'Dei Achilas Pras'.

(b)It may seem strange that the time limit for the large Koseves ha'Gasah should be equivalent to that of the small k'Zayis - but it is nevertheless true.

9)

(a)Chatzi Pras refers to a Kohen who ate half a Pras of Tamei food. He becomes Tamei and is forbidden to eat Terumah (though he does not render anything Tamei by touching it). Rava asked whether it is possible that a 'Chatzi Pras' should have the same time limit (a 'k'Dei Achilas Pras') as the much smaller 'k'Zayis'?

(b)Rav Papa answered that it is not d'Oraisa anyway - meaning that 'Tum'as Gevi'ah' (the body becoming Tamei - in the case of Chatzi Pras) is only mid'Rabanan, and the Rabanan were therefore lenient - despite its large size.

(c)When Rav Papa learnt elsewhere, from "Lo Sitam'u Bahem v'Nitmeisem Bam", that Pesul Gevi'ah is d'Oraisa - he did not mean that it is really d'Oraisa, but that it is an Asmachta.

(d)We actually learn from that Pasuk - that when someone is Metamei himself a little, they cause him from Heaven to become Tamei a lot (i.e. one Aveirah leads to another) - as we learned above on Daf 39a.)

10)

(a)We would have thought that the salt on a raw piece of meat will not combine with the meat to make up a Koseves ha'Gasah - because it is not a food.

(b)It does in fact, combine - because people eat it like that.

(c)We would have thought that brine on top of vegetables should not combine to make up the Shi'ur on Yom Kippur - because, as we have learnt in our Mishnah, food and drink do not combine.

(d)The reason that it does - is because, whatever comes to improve the food (like a sauce) has the Din of a food (and not a liquid).

11)

(a)'Achilah Gasah' on Yom Kippur - is defined as eating after one is already full.

(b)One is not Chayav - because eating in this way is destroying the food and damaging himself, and is not in conflict with Inuy.

(c)Resh Lakish exempts a Zar who eats Terumah b'Shogeg, Achilah Gasah, from having to pay the extra fifth - because a Zar is only Chayav Me'ilah for eating Terumah, but not, for destroying it.

(d)He is nevertheless obligated to pay the principle - because a Zar who damages Terumah is also obligated to pay the principle.

12)

(a)A Zar who chews a raw barley kernel of Terumah b'Shogeg, is not Chayav to pay the extra fifth - because that is not called Achilah.