(Rav): In the bathroom, R. Elazar b'Rebbi Shimon composed a dialogue to prove that a Tevul Yom does not receive a share of Kodshim.

Question: R. Yochanan taught that one may think about Torah anywhere except for a bathhouse or privy!

Answer: Ohnes is different.

Ta'anis 20b: R. Zeira said that one of his merits for long life was that he never thought about Torah in filthy Mavo'os (alleyways).

Berachos 24b (Rav Huna citing R. Yochanan): If one was walking in a filthy Mavoy (at the time of Keri'as Shma), he covers his mouth and says it.

Question: Rav Huna taught that a Chacham may not stand in a filthy place, for he cannot avoid thinking about Torah!

Answer: He may not stand in a filthy place, but he may walk through it while thinking about Torah.

Shabbos 150b (R. Yochanan): R. Yehoshua ben Korchah expounds "v'Daber Davar" - speech (about Melachah) is forbidden on Shabbos, but thoughts are permitted.

Question (Rav Acha bar Rav Huna): This implies that thoughts are not considered Dibur (speech). R. Yochanan forbids thoughts of Torah in a privy due to "v'Hayah Machanecha Kodesh." Here also it says "v'Lo Yir'eh Vecha Ervas Davar" (he should forbid only speech)!

Answer: "Ervas Davar" forbids reciting Shma facing a naked Nochri.

Kidushin 33a: Episodes occurred in the bathhouse in which R. Chiya and Bar Kapara did not stand for R. Shimon bar Rebbi. Rebbi suggested that perhaps they were thinking about what they learned from him, and did not notice him.

One must rise for his Rebbi in the outer rooms of a bathhouse, but not in the inner rooms.

Support: These cases must have been in the outer rooms, for one may not think about Torah in a privy or (inner rooms of) a bathhouse!

Rejection: Sometimes a Chacham cannot avoid thinking about Torah.

Rif and Rosh (Berachos 15b and 3:42): A Chacham may not stand in a filthy place, for he cannot avoid thoughts of Torah. One may think about Torah anywhere except for a bathhouse or Beis ha'Kisei.

Rambam (Hilchos Keri'as Shma 3:4): Even Hirhur (thinking) about Divrei Kedushah is forbidden in a bathhouse or privy or in a place of filth, i.e. excrement or urine.

R. Yonah (Berachos 8b DH Lo): If one may not say a Berachah or Tefilah, e.g. if his hands or the place are not clean, e.g. a Choleh in a dirty bed, he should think the words in his heart. Even though he is not Yotzei, he receives reward for his intent.

Beis Yosef (OC 85 DH Lo): All the Poskim forbid even Hirhur in a place of filth. Perhaps R. Yonah does not refer to true filth.

Magen Avraham (62:2): R. Yonah discusses places such as the middle room of a bathhouse. The Shlah says that R. Yonah means to think about his obligation and regret that he cannot bless. The words of R. Yonah connote otherwise.

Chayei Adam (Nishmas Adam 3:2): Since we hold that thought is not like speech, I am unsure whether the Isur to think about Torah in filthy places is mid'Oraisa or mid'Rabanan. The Gemara said 'Ohnes is different.' It did not say 'it was Ohnes'. This connotes that if the teaching is so fluent in his mouth (or mind) that it comes unintentionally, he need not force himself (to refrain). If it were an Isur mid'Oraisa, surely he would need to pain himself to avoid transgressing! It seems that it is mid'Rabanan, and Chachamim did not require him to pain himself. R. Yonah holds like this; Chachamim did not decree in a case of Ohnes.

Rosh (3:14): R. Yonah learns from Shabbos 150a that Hirhur is not like speech.

Rashi (Shabbos 150a DH v'Hayah): The Machaneh must be Kodesh, for Yisre'elim constantly think about Divrei Torah.

Terumas ha'Deshen (41): One may pray only amidst Halachah that was clearly decided, lest he think about it during Tefilah. We do not say so before entering a bathhouse. We find that great Chachamim were thinking about teachings before entering the bathhouse (Kidushin 33a, Rashi). If it were forbidden to think about them beforehand, we would not say that they were Anusim! If one must dispel thoughts of learning in order to pray, this is distracting. One knows that he may not think Torah in the bathhouse, so he will force himself not to. Also Torah and Tefilah are both Kodesh, so it is hard to avoid thoughts of Torah during Tefilah. It is disgraceful to think Torah in the bathhouse. We say that one who seeks Chametz to destroy it will not come to eat it (and similarly regarding one who tries to avoid thinking Torah in the bathhouse)! However, Rav Huna forbids a Chacham to stand in a filthy Mavoy, for he cannot avoid Hirhur. This requires investigation.

Rema (OC 62:4): If one is in a place that is not totally clean (at the time for Keri'as Shma) and he cannot clean it, he should think Shma in his heart. If it is utterly filthy he may not think about Divrei Torah.

Bach (4): The Isur to think Torah in filthy places is not because thought is like speech. Rather, it is due to v'Hayah Machanecha Kodesh.

Mishnah Berurah (9): If one is obligated to say Shma or a Berachah but may not, he should think about his obligation and feel bad that he cannot fulfill it.

Shulchan Aruch ha'Rav (73:1): If two were sleeping without clothes, covered by one cloth and their bodies touch, they may say Keri'as Shma only if the cloth separates them from the hips and below. If their bodies touch there, this arouses Hirhur, and it is forbidden due to v'Lo Yir'eh Vecha Ervas Davar. Even though the verse discusses exposed Ervah, mid'Rabanan, when "Hash-m Elokecha Mis'halech b'Kerev Machanecha", i.e. when you say Shma, pray or learn Torah, anything that arouses Hirhur is called Ervah, e.g. an exposed Tefach on a woman. However, thinking is permitted even when his Ervah is exposed. Therefore, one may think Kodesh thoughts at the time of relations, for thought is not like speech for this matter, even though it is regarding thinking in filthy places.

Shulchan Aruch ha'Rav (75:10): One may think Torah when he is naked, and all the more so facing Ervah, for it says Ervas Davar - only speech is forbidden. He should not be Yotzei a Berachah through hearing it, for we cannot say that hearing is like answering, for he may not answer.

Mishnah Berurah (79:3): The Pri Megadim says that the Rashba forbids speaking Divrei Torah if excrement is in front of him as far as he can see, but permits thinking Divrei Torah more than four Amos from where the smell ends. Perhaps the Rosh forbids mid'Oraisa or mid'Rabanan.

Shulchan Aruch (84:1): In the middle room of a bathhouse where some people are dressed and some are naked, She'elas (greeting with) Shalom is permitted, but one may not recite Shma or pray.

Rema: One may think Divrei Torah there.

Gra (DH u'Mutar): The Shach (YD 244:4) says that Kidushin 33a permits in the middle room, for there we permit She'elas Shalom. It seems that the Rif, Rosh and other Poskim agree, for they brought this teaching. There is no Chidush in the outer room, for there one may put on Tefilin! The Rambam omitted it, for he holds that the Heter is in the outer room.

Shulchan Aruch (OC 85:2): Even Hirhur about Divrei Torah is forbidden in a privy, bathhouse or in a place of filth, i.e. excrement or urine.

Magen Avraham (2): Hirhur is permitted while facing Ervah, but not in a privy, for it is a place of excessive filth.

Machatzis ha'Shekel: Granted, v'Hayah Machanecha Kodesh forbids Hirhur in a privy. The Magen Avraham needed to explain why it is forbidden in a bathhouse. Due to the heat, there is great filth.

Beis Yosef (DH v'Chosav ha'Rav): R. Mano'ach says that the Yerushalmi permits Hirhur in a privy. The Ra'avad says that the Bavli agrees. It forbids only intentional Hirhur in Torah. If Torah is fluent in one's mouth and he thinks there b'Ohnes, it is permitted. We learn from R. Elazar. The teaching was fluent in his mouth, and he thought about it against his will (Rashi).

Mishnah Berurah (8): 'It is permitted' means that he is not liable, since it was b'Ohnes, but surely he must try to avoid Hirhur.

Kaf ha'Chayim (16): If one starts thinking of a woman or any evil thought, he may divert his mind to Torah, for this is preventing sin.

Mishnah Berurah (15): This is when the place is not totally clean, or his hands, e.g. he touched a covered part of the body. If the place or his hands are filthy, even Hirhur is forbidden.

Shulchan Aruch (554:3): Some forbid learning through Hirhur on Tish'ah b'Av.

Agur (847, citing Maharil 201): Most permit learning through Hirhur, for thought is not like speech. I say that here it is forbidden due to Simchah, which is primarily through Hirhur. One who does not understand has no Simchah!

Magen Avraham (5): Therefore, one may not learn even a Drashah or question and answer in sad parts of Torah, for this brings Simchah. One may not give a ruling, unless needed on the day for a sick person, or for parties in a case who need to go away tomorrow, for giving a ruling is like Hirhur.

Gra: We say 'speech is forbidden but Hirhur is permitted' only regarding Shabbos.

Rema (YD 246:26): A Chacham may not stand in a filthy place lest he think about Torah, but he may enter a bathhouse amidst (any) learning, not only Halachah that was clearly decided. We are confident that he will be careful not to think inside the bathhouse,

Rema (282:19): The Isur to think about Torah in filthy places is due to Kevod ha'Torah.

Pri Megadim (Sof Petichah Klalis, DH Machshavah): Perhaps the Isur to think about Torah in such places is mid'Rabanan.