Related do Berachot 3:7

The grooms and all [others] who are involved in [other] Mitzvot (commandments) are exempt from reading [the] Shema and from [the Amidah] prayer and from Tefillin (phylacteries), as it is said, “… when you sit in your house”, (Deuteronomy 6:7) which excludes grooms, “and when you walk on the way”, (Deuteronomy 6:7) which excludes those who are involved in mitzvot.

The grooms and all [others] who are involved in [other] Mitzvot (commandments) are exempt from reading [the] Shema and from [the Amidah] prayer and from Tefillin (phylacteries), as it is said, “… when you sit in your house”, (Deuteronomy 6:7) which excludes grooms, “and when you walk on the way”, (Deuteronomy 6:7) which excludes those who are involved in mitzvot.

They have buried the dead [person] and lined up in a row. The [outer] row that sees the inner [row] is exempt [from saying the Shema] and the [outer] row that does not see the inner [row] is obligated [to say the Shema]. Rebbi Yehudah says, “If there is only one row there, then those who are standing there for the sake of honor [of the dead] are obligated [to say the Shema], [and those who are standing there] for the sake of the mourner are exempt [from saying the Shema].” [Later] they went down to eulogize [the dead person]. The people that see the inner row are exempt [from saying the Shema], and some say, “those who are behind them [are exempt as well].” And those that do not see the inner row are obligated [to say the Shema]. The one that says the eulogy and all of those who are involved in the eulogy stop [the eulogy] to read the Shema, but they do not stop [the eulogy] to pray [the Shmoneh Esreh]. It happened [once] that the Rabbis stopped [the eulogy] for the reading of the Shema and [the] prayer [of Shmoneh Esreh].

A man who had a seminal emission (Baal Keri) and is sick, if nine Kavs of water were poured on him, he may read [the Shema]. But he may not fulfill the obligation [of reading the Shema] for others until he dips himself in forty Seah [of water]. Rebbi Yehudah says, “Forty Seah no matter what."

A man who had a seminal emission (Baal Keri) and is sick, if nine Kavs of water were poured on him, he may read [the Shema]. But he may not fulfill the obligation [of reading the Shema] for others until he dips himself in forty Seah [of water]. Rebbi Yehudah says, “Forty Seah no matter what."

A man who had a seminal emission (Baal Keri) and is sick, if nine Kavs of water were poured on him, he may read [the Shema]. But he may not fulfill the obligation [of reading the Shema] for others until he dips himself in forty Seah [of water]. Rebbi Yehudah says, “Forty Seah no matter what."

Zavim, Zavot, Niddot, and women who gave birth are permitted to read the Torah and to learn Mishna, Midrash, laws, and Aggadot. And men who had a seminal emission (Baalei Keraim) are forbidden in all of them. Rebbi Yossi says, “He can learn the laws that he is familiar with, as long as he does not arrange the Mishna.”

“A man who had a seminal emission (Baal Keri) who does not have water to dip in may read the Shema, but he may not [read it loud enough so that he can] hear [himself talking] with his own ear, and does not say the Beracha (blessing) not before it and not after it.” [These are] the words of Rebbi Meir. And the Chachamim (Sages) say, ”He may read the Shema and he may [read it loud enough so that he can] hear [himself talking] with his own ear, and he says the Beracha [both] before it and after it.” Rebbi Meir said, “One time we were sitting in the Bet Midrash (Study Hall) in front of Rebbi Akiva and we were reading the Shema, but we were not saying it loud enough to be able to hear ourselves, because of one inquisitor who was standing by the door.” They (i.e. Chachamim) said [back] to him, “The time of danger is not a proof.”

One that was standing in the field naked or that was doing his work naked should cover himself with straw and with stubble or anything [else for that matter] and may read [the Shema]. Even though they (i.e. the Rabbis) said that it is not praiseworthy for a person to be sitting naked, because the Holy One Blessed Be He did not create man naked as it says, “I clothed him in a cloud and [made] mist his shroud.” (Job 38:9) “Clothed him in a cloud” that [refers to] the sack of the fetus, “and [made] mist his shroud” that [refers to] the placenta. [If] there was a wrap of cloth or of skin wrapped around his loins he may read [the Shema]. Either way he should not pray [Shmoneh Esreh] until he covers his heart.

[In order to say Shema or pray Shmoneh Esreh] a person must move away from the feces and urine of a small child who is capable of eating an olive size [piece of bread], four Amot. We only move away from [the feces] of a person and of a dog when skins are placed inside it (i.e. dog feces) [for processing].

[If] an [empty] vessel for excrement or a tub for urine is with him in the house, he should move away [from it] four Amot and read [the Shema]. [If it is] in front of his bed he should put any amount of water into it and read [the Shema], but if he did not [put water in it], he may not read [the Shema]. Rebbi Zakkai says, “If he put into it a Reviit of water he [may] read [the Shema], and if not, he [may] not read the Shema.” Rabban Shimon Ben Gamliel says, “[If the vessel for excrement] is in front of the bed he [may] not read [the Shema], [but] if it is behind the bed he [may] read [the Shema].” Rebbi Shimon Ben Elazar says, “Even if the whole house is approximately ten Amot [long] and the vessel for excrement is put inside it, he [may] not read [the Shema] until he takes it outside or puts it under the bed.”

A person should not go into dirty alleyways and read the Shema [there]. And not only that, but even if he already walked into [a dirty alleyway] while he was reading [the Shema], he should stop [reading it] until he completely exits from that area, and [only then] he [may continue] reading [the Shema]. A person should not stand and pray [Shmoneh Esreh] while he needs to relieve himself, as it is said, “Prepare to greet your God, Yisrael.” (Amos 4:12)

[A person] should not spill water [with feces in it] in a place where he [wants to] pray [Shemoneh Esreh], but rather he should [spill it] four Amot away [from that place]. If [the feces have] dried up or reabsorbed (i.e. dissolved) then it is permitted [to pray Shmoneh Esreh next to them].