first parsha of Shema we are commanded about the mitzvah of talmud Torah, which encompasses man’s entire day: “You shall speak of them while you sit in your home, while you walk on the way, when you retire and when you arise.” (Devarim 6:7)

In Ma’alot Hatorah, R. Avraham, the GRA’s brother, writes an explanation in the name of the GRA:

I heard from my brother, the Gaon z”l, that this refers to the four parts of the day, which is divided into four parts: from the beginning of the night until midnight; from midnight until daybreak; from the beginning of the day until midday; and from midday until the beginning of the night.

“While you sit in your home,” refers to the time from midnight until daybreak, since a person has to rise from his slumber and sit on his bed and learn Torah.“While you walk on the way,” refers to the time from midday until the night, when a person is involved in his business affairs.“When you retire,” refers to the time from the beginning of the night until midnight.“When you arise,” refers to the time from the beginning of the day until midday. (It seems that according to the GRA the morning is called, “when you arise,” not only because of arising from one’s sleep, but because of rising from the bed upon which he sat and learned Torah, or it is talking about the average person who normally arises in the morning.)

This explanation corresponds to a fundamental concept in a person’s way of life, that we find in the name of the GRA in the sefer, Ma’aseh Rav. The first half of the day has to be dedicated to Torah, and involvement in one’s needs or work should be postponed until the second half of the day. Thus, it says in Ma’aseh Rav, in Hilchot Tefillah, #61:

All of a person’s business affairs, mitzvot and nap should be after midday for two hours, not to stop his learning, only to do a mitzvah that will be neglected altogether if he will not do it.

[This guidance has two important elements: 1) The centrality that a person gives Torah relative to his other needs, which is evident through the precedence that he gives it. 2) The clarity of mind of the morning hours is appropriate for learning Torah.]

We can understand the order of the pasuk as going from the most difficult to the easiest. The greatest difficulty is to get up in the middle of the night in order to learn Torah, and, indeed, few are privileged to fulfill this directive. Next is the difficulty of learning Torah when a person is occupied with his dealings (i.e., in the short times that are available while he is involved in his affairs). Next, when a person at home and he is tired, but he does not have the distractions of business and work. The easiest time is the morning hours, which are specifically designated for learning Torah.

However, Ma’alot Hatorah explains that the Torah begins with, “While you sit in your home,” for a different reason: “Since the primary learning is at night, as it says in the Gemara, ‘The night was created only for learning’ (cf. Eruvin 65a), and therefore it begins, ‘While you sit in your home.’”

He further explains in the name of the GRA that these times correspond to the patriarchs and David. Avraham corresponds to the morning, Yitzchak to the afternoon, Yaakov to the evening, and David corresponds to midnight. Each one established a prayer that matches his time. Furthermore, it is possible that this is the idea behind the various names with which the patriarchs called the Beit Hamikdash (i.e., their manner of serving G-d). Avraham called it a “mountain,” which alludes to the Torah that was given at Mt. Sinai, and whose time is the morning, which is designated for involvement in Torah. Yitzchak called it a “field,” which alludes to man’s sustenance. Yaakov called it a “house,” since this is the time that a person enters his house and has to illuminate it with the light of Torah that he learned in the morning and with the sustenance that he attained in the afternoon.

It seems appropriate to connect to this idea also the continuation of the parsha, “Bind them as a sign upon your arm and let them be ornaments between your eyes. And write them of the doorposts of your house and upon your gates.” (Devarim 6:8-9) Here, too, we are commanded  in four practices: tefillin of the arm, tefillin of the head, mezuzot of the house, and mezuzot of the city gates. It seems that also they allude to these four aspects:

“Bind them as a sign upon your arm” alludes to midnight, which is the peak of the attribute of justice, which is the left hand. Indeed, the Gemara Brachot states that at midnight a northern wind would come and blow in David’s harp. The binding is explained in the Kabalistic works as alluding to the binding of justice and the fight against it, and we find that David fought G-d’s wars. Furthermore, the tefillin of the arm correspond to the heart, which is the source of desire, as its says, “Do not explore after your heart.” (Bamidbar 15:39) King David subdued his desire and repented, so that he said about himself, “My heart has died within in me.” (Tehillim 109:22)

“Let them be ornaments between your eyes,” alludes to the morning, the appearance of light, which makes it possible to see. This is the tefillin of the head, which is between the eyes, and with them, “All the people of the land will see that the Name of Hashem is proclaimed over you.” (Devarim 28:10) This is through the observance of the Torah, which is G-d’s Name, and which is meant to be learned in the first half of the day, as explained earlier.

“The doorposts of your house,” alludes to the first half of the night, when a person is in his house.

“And upon your gates” alludes to the city gates, where commerce and business affairs take place.

Thus, we see that the Torah and the remembrance of G-d’s  Name accompany a person throughout the course of his day. At every moment, and in every circumstance, he must not remove his mind from the constant obligation to learn Torah and to remember his Creator and His mitzvot.