Proceeding along this enchanting path, we will now reconcile the fact that HKB”H instructed that the shel rosh be placed “between your eyes.” Yet, as we learned above, anyone who does so is considered a heretic. So, why, indeed, does the Torah specify to don them "בין עיניך"?
To answer this question, we will refer to a teaching in the Gemara (Gittin 60b): "אמר רבי יוחנן, לא כרת הקב"ה ברית עם ישראל אלא בשביל דברים שבעל פה, שנאמר כי על פי הדברים האלה כרתי אתך ברית ואת ישראל". Rabbi Yochanan said: HKB”H only entered into a covenant with Yisrael on account of the Oral Law, as it states (Shemos 34, 27): “For on account of these words have I entered a covenant with you and with Yisrael.”
In Tiferes Yisrael (Chapter 68), the Maharal of Prague explains—as understood by the brilliant author of the Ketzot HaChoshen, ztz”l, in Shev Shematita (Introduction)— that just like Torah she’b’chsav must be written on a “klaf” (parchment); so, too, Torah she’b’al peh must be written on some sort of “klaf”—namely, the mouth of the scholar who engages in the study of Torah she’b’al peh.
Now, from a sefer-Torah inscribed on a parchment prepared from an animal’s hide, the covenant and unique bond that exists between Yisrael and their Heavenly Father is not so apparent. From Torah she’b’al peh, however, that was given to Yisrael to be studied and transmitted orally, this relationship is ever so apparent. When a Jew’s mouth becomes so pure and refined that it serves as a “klaf” for Torah she’b’al peh, the covenant and intimate relationship that exists between Yisrael and HKB”H becomes ever so apparent! This is the message conveyed by Rabbi Yochanan:
“HKB”H only entered into a covenant with Yisrael on account of the Oral Law.”
Based on this, the Shev Shematita goes on to address a statement by Rashbi in the Yerushalmi (Berachos 1, 2): "אילו הוינא על טורא דסיני בשעתא דאתיהיבת תורה לישראל, הוינא מתבעי קומי דרחמנא דיתברי לבר נש תרין פומין, חד דהוה לעי באורייתא וחד דעבד ליה כל צורכיה". Had I been on Har Sinai when the Torah was given to Yisrael, I would have pleaded with HKB”H to create man with two mouths—one to engage in the study of Torah and one to perform all of his personal needs.
Let us elaborate. The “klaf” upon which a sefer-Torah is written must be prepared and processed l’shma, as the halachah dictates (O.C. 32, 8). Similarly, a Jew’s mouth, which becomes the “klaf” of Torah she’b’al peh, should be guarded and prepared l’shma, for the sake of the kedushah of the Torah. This prompted Rashbi to request that a Jew be equipped with a special mouth exclusively for studying Torah; thus, he would not diminish the kedushah of the “klaf” of Torah she’b’al peh by speaking frivolous, improper things
We now have cause to rejoice. For, this enlightens us as to why HKB”H always emphasizes in the Torah that the tefillin shel rosh should be worn "בין עיניך". He meant to impress upon us that the purpose of the “shel yad” opposite the heart and the “shel rosh” opposite the brain, with their forty-two mentions of the holy name, is to sanctify the body’s two sovereign powers—the heart and the brain. Thus, the entire body is sanctified with the kedushah of the “klaf” of Torah she’b’al peh.
Now, in the berachah preceding Krias Shema, we pray: "והאר עינינו בתורתך"—enlighten our eyes with Your Torah. This implies that the strenuous effort and understanding associated with the study of Torah she’b’al peh involve seeing and perceiving with the “eyes” of the intellect. This then is the meaning of the passuk: "והיה לך לאות על ידכה ולזכרון בין עיניך"—and it will be for you a sign on your hand and for a remembrance between your eyes. Then, the passuk goes on to clarify what is meant by “between your eyes”: “So that Hashem’s Torah may be in your mouth”—that you should use your mouth to study Torah she’b’al peh to reveal the true intent of "בין עיניך". Furthermore, with these words, the Torah is informing us that in the merit of donning the tefillin shel yad and shel rosh, a Jew’s mouth and body are transformed into a “klaf” illuminated by Torah she’b’al peh.
