1)

(a)Abaye learns from "O Beged" to include clothes of three by three finger- breadths by wool and linen with regard to Tum'as Sheretz, since the 'Vav' in "ve'ha'Beged" included them only by Tum'as Nega'im.

(b)According to Abaye, we cannot learn Tum'as Sheretz from Tum'as Nega'im, because Tum'as Nega'im is special, inasmuch as the woof and the warp are also subject to Tum'ah, which is not the case by Tum'as Sheretz.

(c)Abaye maintains that we could not have learned Tum'as Nega'im from Tum'as Sheretz either, because 'Sheratzim' are special, inasmuch as they are Metamei with the small Shiur of a 'ke'Adashah' (the size of a lentil) - whilst 'Nega'im' requires a 'ki'G'ris' (the size of a bean). (Tosfos DH 'she'Kein' explains why Rava does not consider this a 'Pircha'.)

2)

(a)Abaye has discovered a second Tana de'Bei Rebbi Yishmael that clashes with the first, including garments made of other materials in the Din of Tum'as Sheratzim from "O Beged". Rava does not consider this a discrepancy at all - because the Tana in the previous Beraisa was referring to clothes of three by three finger-breadths - whereas the Tana in this Beraisa speaks about clothes that are three by three Tefachim.

(b)Rava has now retracted from what he said earlier (on the previous Amud in 6d.), that that was the opinion of Rebbi Shimon ben Elazar, but that, according to Tana de'Bei Rebbi Yishmael, not even other garments of three by three Tefachim, are subject to Tum'as Sheretz. He no longer Darshens the Mi'ut of "Beged Tzemer u'Fishtim".

3)

(a)According to the Gemara's second answer, it is Rav Papa who states the new opinion (Rava remains with his original statement in Tana de'Bei de'Rebbi Yishmael). Rav Papa understands Rebbi Yishmael's statement 'Af Kol Tzemer u'Fishtim' to include - all other clothes by Kil'ayim, to teach us that they are all excluded from the Pasuk "u'Beged Kil'ayim Sha'atnez" (even garments of three by three Tefachim).

(b)In spite of the Pasuk "Tzemer u'Fishtim", Rebbi Shimon ben Elazar (according to Rav Papa) require a special Derashah to preclude garments that are of other materials from the Isur of Kil'ayim - because the Torah writes "Tzemer u'Fishtim" by the Isur of wearing Kil'ayim; but by the Isur of putting Kil'ayim over oneself (e.g. a blanket, which one does not wear), where the Torah writes "u'Veged Kil'ayim Sha'atnez Lo Ya'aleh Alecha" (without specifying to which type of Beged it is referring), we may have thought that all types of garments are included. Therefore Tana de'Bei Rebbi Yishmael writes 'Af Kol Tzemer u'Fishtim', even there too.

(c)But this is a joke, says the Gemara - because if the Torah restricts the Isur of wearing Sha'atnez to wool and linen, then how much more so to the Isur of just placing it on oneself - which surely cannot be more stringent than actually wearing it.

4)

(a)According to Rav Nachman bar Yitzchak, only garments of wool and linen are Chayav Tzitzis.

(b)According to him, if not for the 'Af Kol' of Tana de'Bei Rebbi Yishmael, we would have learnt the Semuchin with regard to the Tzitzis - not the garment. We would have Darshened it like Rava, who learns from that Semuchin, that wool and linen Tzitzis render Yotze garments made of any material; whereas from "ha'Kanaf" - Mien ha'Kanaf, we learn that any other kind of Tzitzis will only render Yotze a garment of the same material as the Tzitzis themselves (e.g. cotton Tzitzis will exempt a cotton garment, but not a linen one).

(c)We cannot include other materials by Tzitzis from the continuation of that Pasuk "Al Arba Kanfos Kesuscha Asher Techaseh Bah" (which is redundant), in the same way as we include other materials by Tum'ah from "O Beged" (because it is redundant) - because we need the Pasuk of "Asher Techaseh Bah" to include the garment of a blind man in the Mitzvah of Tzitzis, so it is not redundant.

(d)"u'Re'isem Oso" comes to preclude a night garment (even when it is worn in the day. Some Rishonim explain a night garment to mean any garment worn at night, even a day garment) from the Mitzvah of Tzitzis.

5)

(a)Since we have one Pasuk to include and one to exclude, it makes more sense to include the garment of a blind person - seeing as his garment is at least visible to others, whereas a night garment is not visible to anybody.

(b)Rav Nachman bar Yitzchak, prefers to include a woolen or linen garment of a blind person from "Asher Techaseh Bah" rather than a garment of other materials, because, since the Pasuk is referring specifically to woolen and linen garments, it is more logical to include woolen and linen garments, than garments of other materials.

6)

(a)Sumchus who says that if someone uses spun wool as Sechach on his Sucah, his Sucah is Pasul - is in fact concurring with Rebbi Shimon ben Elazar, who said earlier that linen (such as raw tufts of flax) cannot be used as S'chach, because it is subject to Tum'as Nega'im, even though it is not subject to Tum'as Sheretz.

(b)We know that that is what Rebbi Shimon ben Elazar meant, because he said 'Chutz mi'Pishtan' and not 'Chutz mi*'Bigdei* Pishtan'; so we see that he is speaking about spun flax, and not clothes made from flax.

(c)According to Rebbi Meir in a Mishnah in Nega'im, the woof and the warp can receive Tum'ah immediately; Rebbi Yehudah agrees by the warp, but, in his opinion, the woof is Mitamei only after he has removed it from the cauldron where it is being bleached, and stalks of flax, according to him, are subject to Tum'ah only after they have been washed. Sumchus, who renders the wool Tamei as soon as it has been spun - holds like Rebbi Meir.

(d)In Rashi's second explanation, when the Gemara asks 'ke'Ma'an', it means -like whom does Abaye (who explains Rebbi Shimon ben Elazar to mean tufts of flax, and not flax garments) hold? And the Gemara answers like the Seifa of the Mishnah in Nega'im, which reads 've'ha'Onin Shel Pishtan, mi'she'Yislabnu' (be'Tanur).

7)

(a)The only derivative of a tree that may be used for the Shabbos lights is flax.

(b)Flax is also the only derivative of a tree that becomes Tamei Tum'as Ohel even when it is fixed to the ground, and requires sprinkling with the ashes of the Parah Adumah on the third and the seventh days.

(c)We learn that flax is considered the derivative of a tree - from a Pasuk in Yehoshua, which writes (with regard to Rachav ha'Zonah and the two spies) "va'Titmeneim be'Fishtei ha'Eitz".