We are currently between two major festivals in the Jewish calendar — the Exodus and the giving of the Torah. During this time, we relive the experience of our ancestors by counting 49 days to the big event.
Imagine you are homeless, living in a wretched state with no hope. Then, out of nowhere, a king comes and brings you to his private room in a magnificent palace, feeds you, gives you his time and a free pass to enter anytime. That is our past and our daily experience:
We were a people with no hope, trapped in Egypt, the lowest spiritual wasteland, then miraculously whisked away, brought to the mountain on Shavuot, given the opportunity to enter a holy environment and engage the Creator whenever we perform a mitzvah. It’s a simple meditation to awaken love and gratitude. It’s reflected before the act of each mitzvah, where we say a blessing “who has sanctified us with commandments.”
When reciting the daily Shema and thinking about the word echad, the soul is said to undergo a mini-Exodus, experiencing the above journey.
Two terms for one
The most fundamental verse and declaration of God’s unity is the Shema: “Hear O Israel, the Lord is our God, the Lord is One.” (Deuteronomy 6:4) The Hebrew word for “one” used here is echad, which connotes a compound unity, bringing together of parts to form a whole. There is another Hebrew word, yachid, which also implies oneness, but an absolute unity, something inherently indivisible.
Now you would think that the command to comprehend an infinite power would use the higher term rather than echad. But there is a greater accomplishment after Creation, when a person is able to look at the world and detect within the diversity and seemingly separate parts how everything is, in fact, being propelled by one force.
Indeed this is the deeper meaning of the statement “one nation on earth” — the capacity of our soul to recognize and reveal the oneness in the multiplicity of earthly things.

Tefillin and time

The main mitzvah — in action, not contemplation — to achieve this awareness of unity is tefillin. The Torah mentions it most explicitly by saying: “You shall tie them as a sign on your hand, and they should be for a reminder between your eyes.” Tefillin consist of two perfectly square black boxes containing specific Torah passages (including the Shema and leaving Egypt), inscribed on parchment, inserted inside each box, and attached with long leather straps.
These boxes (head and arm) are always worn together, but they are actually two distinct commandments. Following the order of the verse, the hand tefillah (singular for tefillin) is always put on first, even though the head is more holy. Scriptural wording offers another clue about their differences. The box must be “tied” on the arm (active) while the other box should simply “be” situated on the head (passive). This language has several practical implications and lessons.
There are certain mitzvahs, such as shaking the lulav, that involve a one-time action and they’re over. Other mitzvahs continue after the initial action, providing an opportunity for fulfillment, like sitting in the sukkah.
A similar distinction can be found between the head tefillah and that of the hand. In theory, once you tie the box to the arm, the mitzvah is complete and one can take it off. In contrast, the head tefillin fulfills a mitzvah every second that it rests there.
Indeed, there was a time period where it was common practice to wear tefillin throughout the entire day, whether in a synagogue, at home, or in the street.

Unity within the individual

One deeper lesson in the box resting on the head and placing the box against the heart has to do with the intellect and emotions. The above theme of unity in Judaism involves not only faith in one God and one Torah, but also unity within the individual person.
There are varying approaches with regard to the best pathway for human conduct: a) Our conduct must be dictated by the cold logic of the mind; b) we should follow our hearts, our lively feelings; and c) what we think and what we feel is not so important; the main thing is the deed — that we act properly.
The Torah’s approach is that a person must be complete and strive for perfection in all three areas. Unfortunately, there often exists a schism between the mind and the heart.
For example, someone may be very strong intellectually but lack emotional maturity, like a cold professor that knows a ton but feels little. Someone else may be deficient in the opposite sense, governed by their instincts and emotions. When the emotions control the mind the intellect is bribed, utilized merely to provide justification instead of striving to be objective.
The first message and meditation of the mitzvah of tefillin is that the head, heart and action must be attuned to each other in order to live a Jewish life. The second message is that the head — remembering the commandments — should penetrate and steer our emotions. We shouldn’t be like a stack of books; we should experience what we learn about. Finally, the tying around the hand symbolizes that knowledge and feelings should culminate in positive action.
While character education takes hard, repeated work to effect change, the mitzvah of tefillin facilitates the attainment of unity of mind and heart, intellect and emotion that lead to action.