IT IS PROPER TO LEARN THE PROPER WAY TO ELIMINATE?
What are 'worldly matters'?
Rashi: They are vain words, not of Torah.
Ha'Boneh: Rabah call anything that is not Divrei Torah 'worldly matters.' His father told him that man's life and health are proper and necessary for a Ben Torah to learn, to enable him to learn Torah! This is unlike business and people's follies. First one fixes the body, and afterwards the Nefesh.
Why did he say 'all the more so you should learn from him!'?
Rav Elyashiv: Guarding your health will enable you to learn more!
MATTERS THAT HELP ONE TO DEFECATE
What is Ru'ach Ra'ah?
Rashi: A bad smell comes from his mouth.
What is Ru'ach Zuhama?
Rashi: His entire body smells from sweat. The odor is absorbed in his flesh and limbs.
Why can he not eliminate?
Rashi: The anus does not open.
What is the meaning of 'he should go to the side'?
Rashi: After checking himself in this corner, he goes to another corner and checks himself.
Why should one eliminate before a fixed meal?
Rashi: It is a disgrace to have to leave in the middle for one's bowels.)
What is the difference between walking four Amos 10 times, or 10 Amos four times?
Rashi: The first way, he stops after every four Amos. The latter way is better - walking a far distance [at once] lowers the excrement to the anus.
TUM'AH OF IDOLATRY
Why was this taught here, in Shabbos?
Rashi: It was taught because it resembles the Mishnah (86a) 'what is the source that we may bathe a recently circumcised baby on Shabbos?'
Tosfos: This is wrong. If so, that Mishnah should have been taught first! Also, both of them should have been taught in Perek R. Eliezer of Milah!
Tosfos: The previous Perek ended with 'the Shi'ur for Cheres... "v'Lo Yimatzei vi'Mchitaso..."' R. Akiva learns from "Tizrem...", which is near that verse.
Rav Elyashiv: Tosfos' primary answer is that both laws are learned from Asmachtos. He adds that the verses are near each other. (NOTE: Many Mishnayos bring Asmachtos! Was not this taught here, for the Asmachta is from a verse nearby?! - PF)
What is Tum'as Masa?
Rashi: One who moves it becomes Tamei.
Daf Al ha'Daf citing Shlah (2:292:1) and the Vilna Gaon (Kol Eliyahu va'Yetzei): Rachel told Lavan "Derech Nashim Li." This was not a lie; she referred to idolatry with her, which is like a Nidah.
Rav Elyashiv: This was before Matan Torah! Idolatry was not yet Tamei like a Nidah! Even though the Avos guarded the entire Torah, i.e. they were stringent to observe the Mitzvos. Tum'ah is a reality! Perhaps the law of Yisrael applied to them as if the Torah was already given, and idolatry truly had Tum'as Nidah. This requires investigation. Or, she told Lavan that she was Nidah, for Chachamim decreed that a Nochris is considered a Nidah - one who has Bi'ah with a Nochris is liable for NaShGaZ (she is considered Nidah, Shifchah, Goyah and Zonah - Sanhedrin 82a).
What is the source that Nidah has Tum'as Masa?
Rashi: She is equated to a Zav, about whom it says "veha'Nosei Osam..." (becomes Tamei).
Is the Hekesh of Nidah to idolatry only for Tum'as Masa?
Ra'avad (Tamid 33a, cited in Pri Chadash OC 128:30) brings from Sefer ha'Miktza'os that a Kohen in the house of his wife, mother or sister who is Nidah, may not Duchan (give Birkas Kohanim). The Ra'avad asked, we permit seclusion with a Nidah! Perhaps it is Midas Chasidus. However, R. Yudan forbids any Kohen to Duchan! I say that "v'Hizartem Es Bnei Yisrael... b'Tam'am Es Mishkani" obligates extra distancing from all that pertains to the Mikdash; Birkas Kohanim is primarily in the Mikdash. R. Akiva equates idolatry to Nidah, to teach that one must distance her even from the house, and for Mitzvos Kehunah, mid'Rabanan Nidah is Metamei b'Ohel, like idolatry, which is equated to Mesim - it is called Zivchei Mesim. However, it is astounding to say so nowadays! Perhaps it was only when Kohanim said Hash-m's name in the Mikdash.
Daf Al ha'Daf: Chasam Sofer (here and Teshuvah OC 23) was astounded at the Ra'avad. Maharsham (8:25, citing Machazik Berachah) points out that Tanchuma (Metzora 18) permits a Kohen Gadol to enter a house with a Nidah and sit near her!
Why must one make idols foreign to himself?
Ha'Boneh: Stam Aveiros, one must distance from them according to the time and person. Idolatry opposes all the Mitzvos! One who admits to idolatry is like one who denies the entire Torah. Rabah adds to R. Akiva. One has connection to [Ishto] Nidah, for later she will be permitted to him. One who believes in Hash-m should never have any connection to idolatry.
What need is there to say 'do not tell it to enter'?
Gilyonei ha'Shas (Gitin 2a, b'Sof): One must enter (have Bi'ah with) a Nidah for Piku'ach Nefesh, e.g. Nochrim threaten to kill him if he will not. One may not do idolatry, even in such a case.
Daf Al ha'Daf citing Kovetz Tzefunos 2, p. 50: Radak on the verse explains "Tzei" to mean leave. Or, it is an expression of Tzo'eh (excrement). Rabah added 'do not tell it to enter' to teach the former way.