Commandment 10 To Read Shema

That is that He commanded us to read the recitation of Shema in the evening and the morning. And that is His saying, "and you shall speak about them" (Deuteronomy 6:4). And the regulations of this commandment have already been explained in Tractate Berakhot; and there (Berakhot 21a), it is explained that the recitation of Shema is [an obligation] from the Torah. And it is written in the Tosefta (Tosefta Berakhot 3:1), "Just like the Torah established [a set time for] the recitation of Shema, so too did the Sages establish a time for prayer." This means to say that the times of prayer are not from the Torah - though the actual obligation to pray is from the Torah, as we explained (Sefer HaMitzvot, Positive Commandments 5) - and the Sages, may their memory be blessed, arranged times for them. And this is the content of their saying (Berakhot 26b), "They established the prayers corresponding to the daily sacrifices" - meaning, that they fixed their times according to the times of the sacrifices. And women are not obligated in this commandment. (See Parashat Vaetchanan; Mishneh Torah, Reading the Shema 1.)

We [are obligated to] recite the Shema twice daily - in the evening and in the morning - as [Deuteronomy 6:7] states: "...when you lie down and when you rise" - i.e., when people are accustomed to sleep - this being the night - and when people are accustomed to rise, this being daytime.

And what is it that one recites? These three sections:
"Hear O Israel..." (Deuteronomy 6:4-9),
"And if you will listen..." (Deuteronomy 11:13-21),and
"And God said..." (Numbers 15:37-41).
We begin with the section of "Hear O Israel" since it contains [the concept of] the unity of God, [the commandment of] loving Him and the study of Torah, it being a fundamental principle upon which everything is based.
After it, [we read] "And if you will listen...," since it contains the imperative to fulfill the rest of the commandments, and finally the portion of tzitzit, since it also contains the imperative of remembering all the commandments.

Hear, O Israel! יי is our God, יי alone. You shall love your God יי with all your heart and with all your soul and with all your might. Take to heart these instructions with which I charge you this day. Impress them upon your children. Recite them when you stay at home and when you are away, when you lie down and when you get up. Bind them as a sign on your hand and let them serve as a symbol on your forehead; inscribe them on the doorposts of your house and on your gates.

If, then, you obey the commandments that I enjoin upon you this day, loving your God יי and serving [God] with all your heart and soul, I will grant the rain for your land in season, the early rain and the late. You shall gather in your new grain and wine and oil— I will also provide grass in the fields for your cattle—and thus you shall eat your fill. Take care not to be lured away to serve other gods and bow to them. For יהוה’s anger will flare up against you, shutting up the skies so that there will be no rain and the ground will not yield its produce; and you will soon perish from the good land that יי is assigning to you. Therefore impress these My words upon your very heart: bind them as a sign on your hand and let them serve as a symbol on your forehead, and teach them to your children—reciting them when you stay at home and when you are away, when you lie down and when you get up; and inscribe them on the doorposts of your house and on your gates— to the end that you and your children may endure, in the land that יי swore to your fathers to assign to them, as long as there is a heaven over the earth. If, then, you faithfully keep all this Instruction that I command you, loving your God יי, walking in all God’s ways, and holding fast to [God],

יי said to Moses as follows: Speak to the Israelite people and instruct them to make for themselves fringes on the corners of their garments throughout the ages; let them attach a cord of blue to the fringe at each corner. That shall be your fringe; look at it and recall all the commandments of יי and observe them, so that you do not follow your heart and eyes in your lustful urge. Thus you shall be reminded to observe all My commandments and to be holy to your God. I יי am your God, who brought you out of the land of Egypt to be your God: I, your God יי.

The commandment of tzitzit is not obligatory at night. Nevertheless, we recite [the section describing] it at night because it contains mention of the exodus from Egypt.
We are commanded to mention the exodus both during the day and at night as [Deuteronomy 16:3] states: "In order that you shall remember the day of your leaving the land of Egypt all the days of your life."
Reading these three sections in this order constitutes the recitation of the Shema.

When is the [proper] time for the recitation of Shema at night? The commandment [starts] from the time of the appearance of the stars [and continues] until midnight.
A person who transgresses and delays fulfills his obligation if he recites [the Shema] before dawn. [The Sages established the limit] of midnight only in order to distance us from negligent wrongdoing.

When is the proper time [for the recitation of the Shema] during the day? The commandment is that one should start to read before sunrise in order to conclude and recite the last blessing with the sunrise. This measure [of time] is one-tenth of an hour before the sun rises.
A person who delays and reads the Shema after the sun rises fulfills his obligation, for the proper time is until the end of the third hour of the day for one who transgresses and delays.

One who recited [the Shema] after [the end of] the third hour, even if he was unavoidably detained, does not fulfill his obligation to recite the Shema at its proper time. He can be compared to one who studies Torah.
He should recite the blessings preceding it and after it all day, even if he delays and recited it after [the end of] the third hour.

One who recites the first verse of Kri'at Shema - i.e., Shema Yisrael... - without intention, does not fulfill his obligation. [One who recites] the rest without intention fulfills his obligation.
Even a person studying Torah in his usual way or proofreading these portions at the time of Kri'at Shema fulfills his obligation provided he concentrates his intention for the first verse.