Rabbi Aba sent a message to Rabbi Shimon, saying that they learned from him that the head Tefillin with the Torah text has the aspect of holy of holies. And how do we know that the leather of the Tefillin house has an aspect of holiness? He added that Rav Hamnuna Saba explains that the Tefillin of the head reveals four lights of Zeir Anpin, which are Chokmah, Binah, Tiferet and Malchut of Da’at, and the leather is Malchut of Zeir Anpin.
“וַיַּעַשׂ יְהוָה אֱלֹהִים לְאָדָם וּלְאִשְׁתּוֹ כָּתְנוֹת עוֹר וַיַּלְבִּשֵׁם.”
“And YHVH God made garments of skin (Leather) for Adam and his wife and clothed them.”
The word ‘עור’ ‘skin’ is the same word used to describe the skin of the animal that is processed as leather. The ‘skin’ that is the ‘garments’ of the corporeal body is the aspect of Malchut.
“וְהָיָה לְאוֹת עַל יָדְכָה וּלְטוֹטָפֹת בֵּין עֵינֶיךָ כִּי בְּחֹזֶק יָד הוֹצִיאָנוּ יְהוָה מִמִּצְרָיִם.”
“It shall be as a mark on your hand (יָדְכָה) or frontlets between your eyes, for by a strong hand YHVH brought us out of Egypt.”
The word your hand is properly written as “יָדֶךָ” but in this verse, it is spelled with added H ה to imply the connection of the Tefillin to Malchut.
Rabbi Shimon says that if we consider the second paragraph of the Shema “והיה אם שמוע” (Deuteronomy 11:13-21) that is one of the Torah text in the head Tefillin as the aspect of the Left hand of YHVH and the sefira of Gevurah then the Light from the first three chambers of the head Tefillin (See chart in #87) would be Chokmah, Binah, and the Right of Chessed, missing the fourth Light that is the Left of Da’at.
If we consider “והיה אם שמוע” as Gevurah in the body then we have two holy chariots, one of the head Tefillin and one of the hand.
The head Tefillin is on the brain for Zeir Anpin and the hand is Malchut against the heart. They connect in one unification that is called a ‘mark on your hand’ that reveals Light in Malchut.