1)

(a)Rebbi learns from a Gezeirah-Shavah "Chet" "Chet" from Terumah, that Me'ilah b'Meizid is Chayav Misah. But from the same Gezeirah-Shavah we should learn that Me'ilah, like Terumah, is only Chayav when there is a k'Zayis - so, how can we establish the Beraisa (which considers Me'ilah more stringent because it carries a Chiyuv Misah), by less than a k'Zayis?

(b)Rav Papa answers that Rebbi perhaps holds like Aba Shaul - who considers the criterion of Chiyuv by Terumah, a Perutah, even if it is less than a k'Zayis, in which case, he will apply the same conditions to Me'ilah, thereby resolving the above explanation.

(c)And this proves that Rav Papa must have retracted from his original stance - that Aba Shaul requires both a Shaveh Perutah and a k'Zayis.

2)

(a)Mar B'rei d'Rabana establishes the case where Me'ilah is Chayav Misah and other Mitzvos are not, by 'Eino Miskaven' - with regard to Shabbos, someone who intended to cut something that was detached, and he inadvertently cut something that was attached, he is Patur, because it is not included in 'Meleches Machsheves', and from "Asher Chata Bah" by other Mitzvos. (See Tosfos DH 'Niskaven', who establish the case when he meant to cut something that he believed to be detached, and then after picking it up, he discovered that it had actually been attached.

(b)The case by Me'ilah is - when he intended to pick up some Chulin shearings of wool to use, but inadvertently picked up shearings that were Hekdesh. Me'ilah is more stringent in this case - because the Torah writes "v'Chat'ah bi'Shegagah", no matter how.

(c)According to Rav Nachman bar Yitzchak, one will be Chayav in the previous case, even by other Mitzvos - because his intention to cut renders it is included in 'Meleches Machsheves' and in "Asher Chata Bah" .

(d)The case where Me'ilah is more stringent than other Mitzvos, according to him - is when he intended to pick up something that was Hekdesh, and he inadvertently put his hand into a jar of Hekdesh oil, where he will be Chayav (even though he had no intention of anointing his hand at all); whereas if he meant to pick up something that was detached, and he inadvertently detached something that was attached, by Shabbos and by other Mitzvos he will be Patur.

3)

(a)We learn from the Pasuk "Reishis Degancha ... Titen Lo" - 'Lo, v'Lo l'Oro'. In other words, Terumah does not take effect if it was separated initially from a fruit that was not fit to eat, only to burn - i.e. if it was Chametz at the time when it was designated.

(b)When the Beraisa says 'Ein Tormin min ha'Temei'ah Al ha'Tehorah, v'Im Taram b'Shogeg, Terumaso Terumah' - it is referring to fruit that had a time when it was Tahor, whereas the Derashah of 'Lo v'Lo l'Oro' pertains only to fruit that had always been Tamei (i.e. if it became Chametz whilst still attached to the ground).

(c)If the wheat became Chametz between the time it was picked and the 'Digun' - the Terumah is effective (though the reason for this is unclear).

(d)b'Shogeg' in the above Beraisa means that he was unaware that the Tevel was Tamei.

4)

(a)When Rav Nachman bar Yitzchak said 'bi'Gezeiras Irin Pisgama, u've'Ma'amar Kadishin She'ilta' - he was referring not to angels, but to the Talmidei-Chachamim, who are compared to angels.

5)

(a)'she'Shireha Nikarin l'Yisrael' - implies that the Terumah given to the Kohen is the first, and that the remainder is recognizable as having become permitted to the Yisrael. But if someone designates Terumas Chametz, even according to Rebbi Yosi Hagelili, nothing has become permitted; the Tevel was Mutar b'Hana'ah, and what remains is also Mutar b'Hana'ah, but not ba'Achilah.

(b)According to Rav Nachman bar Yitzchak - the Terumah will not be effective even if the crops became Chametz after they were detached.

6)

(a)Rav Acha bar Rav Ivya quoting Rebbi Yochanan, says that if grapes become Tamei, one may press them less than a k'Beitzah at a time, and the wine will be Kasher for the Nesachim - because he holds 'Mashkin Mifkad Pekidi' (the wine contained inside the grapes is considered as if it was deposited there - and is not considered an intrinsic part of the grapes).

(b)If there was exactly a k'Beitzah of grapes - the wine would also be Kasher for the Nesachim.

(c)Rebbi Yochanan said specifically less than a k'Beitzah - since the Mishnah in Taharos only permits the wine b'di'Eved; l'Chatchilah, it is forbidden to press them, whereas Rebbi Yochanan is informing us what the Din will be if someone comes to ask l'Chatchilah.

7)

(a)Less than a k'Beitzah of food cannot transmit Tum'ah - because the Torah writes "Asher Ye'achel", from which Chazal derive that food that can be eaten in one go can transmit Tum'ah (but not less); and we no for a fact that the human throat can hold the maximum of a chicken's egg. (Note: As far as receiving Tum'ah is concerned, Rashi begins here by saying that even less than a k'Beitzah of food can receive Tum'ah. He concludes however, that he heard that it cannot - see Tosfos DH l'Eimas'.)

(b)The minimum Shi'ur for a liquid to transmit Tum'ah - is a Revi'is (ha'Lug).

(c)According to Rav Chisda - the wine contained inside the grapes is considered an intrinsic part of the grapes, in which case, it will have become Tamei together with the grapes, and pressing them less than a k'Beitzah at a time will not, of course, remove that Tum'ah.

(d)Rav Chisda will explain the Mishnah in Taharos 'Tamei Mes she'Sachat Zeisim va'Anavim, k'Beitzah Mechavenes, Tehorim' - by grapes that were not yet Huchshar Lekabel Tum'ah. Consequently, when the first drop emerged from the grapes (rendering them Muchshar), only less than a k'Beitzah remained, too small a Shi'ur to become Tamei.

8)

(a)If 'Mashkei Mifkad Pekidi', then why would the Beraisa state that berries or grapes that became Tamei do not have a Heter Achilah? Why can they not be pressed less than a k'Beitzah at a time?

(b)Even if we were to hold 'Mashkei Mivli Beli'i', says Rava, the Beraisa would nevertheless be justified in stating that berries or grapes that became Tamei do not have a Heter Achilah - since it is forbidden to retain them because of Takalah (as we learnt above, on Daf 20b).

(c)The Beraisa nevertheless permits the use of Terumah bread and oil that became Tamei, as fuel - because it is possible to throw the bread in the wood-store among the pieces of wood, where it will become dirty and unappetizing; and to place the oil into ugly vessels, with a similar effect.

(d)Rebbi Yochanan permits using wheat kernels of Tamei Terumah as fuel - because one can first burn them and then throw them in the wood-store, where they will become dirty and unappetizing; Rav Huna forbids it, because he is afraid that, by the time one has executed the two requirements, he may come to eat them.