It is a Torah obligation to put on tefillin every weekday of the year. If a man fails to put on tefillin, the Talmud tell us, he causes untold damage to his soul (Tr. Rosh Hashana 17a).
How long should the tefillin be worn?
Ideally, the tefillin are worn the entire day. Such was the practice in ancient times, but nowadays only rare individuals perform the mitzvah in this way. This is because the requirements that one remain conscious of wearing the tefillin, and avoid frivolity during this time, are beyond the reach of most people.
Minimally, the tefillin may be put on for a few moments, as the wearer recites the Sh'ma.
But today the universal practice is to wear the tefillin during morning prayers. In so doing, we perform not one, but eight mitzvos simultaneously during this precious hour or so at the beginning of our day!
All four pieces of parchment contain passages from the Torah. The first two speak of the selection of the Jewish people by Hashem. The first focuses on the rescue from Egyptian slavery, the second on the killing of the Egyptian firstborn because of Pharaoh's stubborn refusal to release Hashem's "firstborn," the people of Israel.
The first two passages (parshiyos) lead naturally to the third: Sh'ma Yisrael. In response to Hashem's selection of us, we show our loyalty to Him. He is our Leader, our G-d and there is none other besides Him. We love Him with all our being, just as He loves us.
The fourth passage completes the set. It speaks of the obligation which grows out of and furthers our relationship with Hashem. The obligation, in a word, is called Mitzvos. We are commanded to fulfill the Mitzvos, the precepts of the Torah, for our own good, for our own happiness. If we fail to do so, we lose out on all the benefits, of course. And we also incur punishment. In this final passage, V'haya im shamo'a, the principal of Reward and Punishment is clearly spelled out.
That, in brief, is the message contained within the tefillin. Of the deeper meaning of the four passages and the boxes in which they are contained, volumes have been written. The holy Zohar, for example, speaks in mystical terms about how the four passages reflect the Tetragrammaton, the four-letter Name of Hashem, and how they connect the wearer with the Creator. Rabbi Yitzchak Luria, known as the Ari, wrote of the mystical implications of every aspect of tefillin. This is hardly the place to go into detail. But let us simply note that the effect of the Mitzvah of Tefillin reaches the illuminated higher spiritual worlds. The reflected light, in turn, touches and elevates the human soul and psyche.
Because of the crucial role they play in the spiritual life of the Jew, tefillin need to be kosher in every detail. For example, the parchment on which the four passages is written must be processed specifically for the sake of the Mitzvah of Tefillin. And the scribe who writes the passages, must be expert in thousands of laws which govern the form of the letters and their writing. He himself writes with the sanctity of the mitzvah in mind, and when he reaches the Name of Hashem, he must articulate his holy intent aloud. If it should happen that he writes out the Name of Hashem without the proper intent, the parshiyos cannot be used!
Ditto if even one mistake is discovered. Since the parshiyos must be written in order, they cannot be repaired. Thus, it sometimes happens that hours of hard, painstaking work, go for naught. (It should be obvious, then, that only a G-d-fearing scribe can be relied upon to produce parshiyos whose kashrus – both visible and invisible – is impeccable). Once they are written, the parshiyos are submitted to an expert proofreader for checking. He carefully reviews the letters, one by one. If he discovers a disqualifying mistake, the parshiyos may not be used. If he encounters a borderline case, he turns to a qualified Rabbi for a verdict.
Only after the parshiyos have been approved, are they inserted into the "black boxes" of the tefillin, in the specified order. The boxes are then sewn up according to specified regulations with a special type of string. If all is not done properly, in the manner spelled out at Sinai, the resulting unkosher tefillin will not bring the spiritual bounty they are meant to.
Like a Spiritual Transistor
Perhaps we can better appreciate why tefillin have to be made just so by recalling the response of the saintly Rabbi Eliyahu Dushnitzer to one of the early transistor radios. Walking in Petach Tikvah about fifty years ago, he passed a young man at a bus stop with a transistor radio glued to his ear.
"What is that?" the Rabbi asked his escort.
"It's a transistor."
Rav Dushnitzer's escort explained that a transistor was a cordless radio that operates on batteries.
"I don't quite understand," said the Rav, "how it works without electrical wires."
"Neither do I," the escort acknowledged, but pointed out that the wires and circuitry within must do the job. "After all, it works."
The Rav pressed his escort about the flexibility of the internal wiring arrangements.
"If a single wire gets disconnected," came the response, "the radio will go silent…"
"If that is the case," responded Rav Dushnitzer, "I cannot understand why people are so surprised that a small crack in one letter of the parshiyos of tefillin, renders the tefillin unkosher – not to mention missing or extra letters… After all, the tefillin are sort of like a spiritual transistor, connecting man with the upper spiritual worlds. To work, every 'contact point' must be just right…"