There is some evidence that the Torah intended the idea of tefillin (totafot in the Shema, sometimes translated as “phylacteries”) metaphorically. Inner biblical exegesis — comparison with other parts of the Bible — gives us an insight into this.
Take these verses for example: “My son, keep your father’s commandment. Do not forsake your mother’s teaching.
“Tie them over your heart always. Bind them around your throat.
“When you walk it will lead you. When you lie down it will watch over you. And when you are awake it will talk with you” (Proverbs 6:20-22)
This sounds like we should carry the Torah’s teachings with us conceptually, and not necessarily literally, as we go about our lives.
And yet tefillin — and mezuzah too — are commandments that we observe using actual objects. These objects resemble protective amulets, like those used in other ancient Middle Eastern cultures, a fact the rabbis aren’t completely comfortable with.
In ancient times tefillin were probably worn by men all day, not just for prayers. During the day women and children were mostly at home and so the mezuzah on the doorpost would protect them, negating their need for personal protective equipment.
This explains why women and children aren’t traditionally required to wear tefillin. There is no mitzvah to wear tefillin at night, and of course this fits well with the fact that after dark men would be home too — safely in the protective zone of the mezuzah.
Even without the religious texts they contain, tefillin and mezuzah have a kind of talismanic, protective function. I find it illuminating to think of tefillin as jewellery. Jewellery is enduring. Jewellery is worn close to the body, imparting an aura that travels two ways : from the wearer to the piece of jewellery and from the piece of jewellery to the wearer.
An heirloom piece of jewellery is a tangible connection to a loved one who once wore it.
When donning the arm tefillin we wind the straps around our hands and fingers, reciting lines in which we “marry” God. The head tefillin feel a little like wearing a crown. Tefillin are ancient and mysterious and also among our most embodied mitzvot.