it, so too, Hashem, Who is represented by the tefillin, is eternally one. The color black also symbolizes the depth and concealment of their meaning. The four-sided cubic shape of the tefillin boxes alludes to four-letter name of Hashem. The shin on the right side has three heads, corresponding to the three Patriarchs, on the shin on the left side has four heads, corresponding to the four Matriarchs, in whose merit the Divine Presence rests upon the Jewish people. The boxes are sewn with twelve stitches, four on each side, alluding to the twelve tribes of Israel, who encamped on the four sides of Mishkan. In addition, the gematria value of two shin’s and three and four is 613; thus, the tefillin allude to our obligation to observe 613 mitzvos.
The straps of the head-tefillin extend downward, alluding to that which Hashem’s Presence fills the world and controls it. The strap on the right side extends at least until the navel, symbolizing that Hashem’s dominion on high extends down to earth, and especially to the center of the world, Eretz Yisrael.
The tefillin thus serve to elevate us and to distinguish us from amongst the nations that do not share our bond with the Creator. With regard to the head-tefillin, which is displayed for all to see, the verse states: “Then all the peoples of the earth will see that the name of Hashem is proclaimed upon you, and they will revere you.”
Sources: Rashi and Chizkuni to Shemos 13:9; Tosafos to Menachos 34b; Shoshanim LeDavid; Aruch (tafel); Mayim Chaim, by Rabbi Yosef Masas (Orach Chaim §38); see also Pri Megadim (Orach Chaim §25, Eishel Avraham §8); Maharal, Gevuros Hashem (Ch. 39); Chinuch; Zohar cited in Beis Yosef (Orach Chaim §31); Rav Shimshon R. Hirsch (Devarim 6:8); Menachos 37b; Chizkuni (13:16); Tzror HaMor to Shemos 13:5; Maadanei Melech to Devarim 6:8; Kuzari (3:11); Alshich (11:18); Chidushei Aggados L’Rashba (Berachos 6a); Eliyah Rabbah (Orach Chaim §25); Rabbeinu Bachya (Shemos 13); Ateres Zekeinim §11; Tzioni to Shemos 12:12; Eliyah Rabbah (see also Beis Yosef §32); Raavan in his commentary to the prayer “Shochen ad”; Kad HaKemach; Matteh Moshe (Tefillin §16); Beis Yosef (Orach Chaim §31).
