From when may we recite the Shema in the evening? From the time that the Kohanim enter to eat their terumah. [And We may recite it]. Until the end of the first watch. [These are] the words of R’ Eliezer. But the Sages say: Until midnight. Rabban Gamliel says: Until the light of dawn rises. It happened that his sons came [home] from a banquet. They said to him: We have not [yet] recited the Shema. He said to them: If the light of dawn has not yet risen, you are obligated to recite. And not only this, but all things about which the Sages said ‘‘Until midnight,’’ [the time for fulfilling] the commandment extends until the light of dawn ris-es. [For] the burning of [the sacrificial] fats and limbs [on the Altar, the time for fulfilling] the commandment extends until the light of dawn rises; and [for] all [the sacrificial parts] that are eaten for one day, [the time for fulfilling] the commandment extends until the light of dawn rises. If so, why did the Sages say: ‘‘Until midnight’’? In order to distance a person from transgression.

From when do we recite the Shema in the morning? From when one can distinguish between techeiles and white. R’ Eliezer says: between techeiles and leek. And one must finish it by sunrise. R’ Yehoshua says: By three hours, for such is the way of princes, to rise by three hours. One who recites from then and onward does not lose; [he is] like a person reading from the Torah.

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.