Beis Shammai say: In the evening all people must lie down and recite [the Shema], and in the morning they must stand, for it is stated: When you lie down and when you arise (Deuteronomy 6:7). But Beis Hillel say: Every person recites according to his [preferred] manner, for it is stated (ibid.): While you walk on the way. If so, why is it stated: When you lie down and when you arise (Deuter-onomy 11:19)? At the time when people go to sleep and at the time when people get up. R’ Tarfon said: I was coming on the road, and I lay down to recite in accordance with the words of Beis Shammai, and I endangered myself on account of the bandits. They said to him: It would have been fitting for you to come to harm, for you trans-gressed the words of Beis Hillel.

In the morning one recites two blessings before [the Shema] and one after it, and in the evening [one recites] two [blessings] before [the Shema] and two after it; one lengthy [blessing] and one brief [one]. Where they said to recite a lengthy [blessing], one may not shorten [it]; [where they said] to recite a brief [blessing], one may not lengthen [it]. [Where they said] to con-clude [a blessing] with a closing formula, one may not conclude [the blessing] without the closing formula; and [where they said] not to conclude [a blessing] with a closing formula, one may not conclude [the blessing] with a closing formula.

We mention the Exodus from Egypt at night. R’ Elazar ben Azaryah said: Behold, I am like a seventy-year-old man, yet I did not prevail [with my argument] that the Exodus from Egypt should be mentioned at night, until this was expounded by Ben Zoma: For it is stated: So that you will remember the day of your departure from the land of Egypt all the days of your life (Deuteronomy 16:3.). The days of your life — [this means] the days; all the days of your life — [this includes] the nights [also]. But the Sages say: The days of your life — [this means] this world; all the days of your life — [this comes] to include the days of the Messiah.

[If] one was reading from the Torah and the time arrived for the recital [of the Shema], if he directed his mind [properly], he has discharged his obligation; but if not, he has not discharged his obligation. At junctures [between sections of the Shema or its blessings] one may greet [an-other] out of respect, and he may reply [to a greeting]; but in the middle [of a section] he may greet [another only] out of fear and he may reply. [These are] the words of R’ Meir. R’ Yehudah says: In the middle [of a section] he may greet [another only] out of fear but he may reply out of respect; at junctures [between sections], he may greet [another] out of respect and he may reply with a greeting to any person.

These are between the sections [of the Shema and its blessings]: Between the first blessing and the second [blessing]; between the second [blessing] and [the passage of] ‘‘Shema’’ (Deuteronomy 6:4-9); and between ‘‘Shema’’ and [the passage of] ‘‘Vehayah im shamoa’’ (Deuteronomy 11:13-21); between ‘‘Vehayah im shamoa’’ and [the passage of] ‘‘Vayomer’’ (Numbers 15:37-41); between ‘‘Vayomer’’ and [the blessing of] ‘‘Emes Veyatziv.’’ R’ Yehudah says: Between ‘‘Vayomer’’ and ‘‘Emes Veyatziv’’ one may not in-terrupt. R’ Yehoshua ben Korchah said: Why does [the passage of] ‘‘Shema’’ precede [the passage of] ‘‘Vehayah im shamoa’’? Only so one will first accept upon himself the yoke of Heaven’s sovereignty, and afterward accept upon himself the yoke of [the] command-ments. And [why does] ‘‘Vehayah im shamoa’’ [precede the passage of] ‘‘Vayomer’’? Be-cause ‘‘Vehayah im shamoa’’ applies by day and by night, [whereas] ‘‘Vayomer’’ applies only by day.

[If] one recites the Shema and does not make [it] audible to his ears, he has discharged [his obligation]. R’ Yose says: He has not discharged [his obligation]. [If] he recited [the Shema] but was not meticulous in [enunciating] its letters, R’ Yose says: He has discharged [his obligation]. R’ Yehudah says: He has not discharged [his obligation]. [If] one recites [the Shema] out of sequence, he has not discharged [his obligation]. [If] one recited [the Shema] and erred, he must return to the place where he erred.

Workers may recite [the Shema] on top of a tree or on top of a wall, which they are not permitted to do with regard to prayer.