Parshas Reeh (5775)
One of the 613 commandments for a Jewish male is to wear Tefillin (phylacteries) -special leather boxes and straps placed on one's head and arm - each and every day except Shabbos and holidays, as the Torah says: "Bind [these commandments] as a sign on your arm, and let them be ornaments between your eyes" (Deuteronomy 6:8).
Additionally, the Torah commands the Jewish people in Exodus 13:9: �And it shall be for you a sign on your arm and a reminder between your eyes�� and again in Exodus 13:16: ��And it shall be a sign on your arm, and an ornament between your eyes��
It would seem from a simple reading of the texts that one should place the head-tefillin directly between the eyes. In fact, the Sadducees, a long-gone break-off movement of Jews who preached a literal reading of the Torah, did just that � they wore their Tefillin right between the eyes, just as it says in Scripture.
However, we have a 3327-year-old (!) Oral Tradition from Moses at Mount Sinai that the box of the head-tefillin should be placed just above the hairline (i.e. where it is resting entirely on hair), directly above the space between the eyes. [One who is balding should put it on a location where there used to be hair.]
The strap of the head-tefillin forms a large loop which rests on the crown of the head. At the other end of the loop is a knot that should be positioned on the nape of back of the head, above the hairline. Both the box and the knot should be at the center of the head, i.e. equally centered between right and left. The straps of the Tefillin are always arranged so that the smooth black side is facing outward. The two straps of the head-tefillin should hang down in front of the person.
To learn more about the beautiful mitzvah of Tefillin, and to see some fascinating videos illustrating the process of making Tefillin as well as how to put them on properly, click on: http://www.aish.com/jl/m/pb/48969816.html.
[Sometimes I see men who come to shul once a year to say kaddish on the yahrtzeit (anniversary of death) of a departed relative, and they put Tefillin on for the occasion, yet out of ignorance they wear the box of their head-tefillin way beneath their hairline and almost between their eyes. According to Halachah (Jewish law) it is far more important that the box of the head-tefillin be worn above the hairline than it is for it to be centered between right and left. It is appropriate to respectfully clarify to these men where the Tefillin should be placed so that they will be fulfilling this precious mitzvah properly.]
Of course the obvious question is that if G-d intended that Jewish men wear their head-tefillin above the hairline instead of directly between the eyes, then why did He instruct Moses to write in the Torah (in three places, no less!) that it should be worn �between the eyes�?!
Nachmanides (1194�1270), a leading medieval Jewish scholar, philosopher, physician, kabbalist, and biblical commentator, interprets the words in Exodus 13:9: �and a reminder between your eyes� to mean �the place of remembering that is between your eyes�. This refers to the brain, which stores the sights that the eyes see.
As Rabbi Dovid A. Gross writes in his wonderful book 30 Days to Bar Mitzvah: An Illuminating Guide to the Mitzvah of Tefillin, the Tefillin is placed on the top of the head on the spot underneath which lies the frontal lobe of the brain. This lobe plays an important role in short- and long-term memory function. The straps of the Tefillin then wrap around the entire head and brain, ending with the knot at the back, on the spot underneath which lies the occipital lobe of the brain. This lobe is the visual processing center of the brain. The head-tefillin is thus the �place of remembering� as it encompasses the visual and memory centers of the brain.
Nachmanides explains further (see his commentary to Exodus 13:16) that when the Torah writes that the head-tefillin should be placed �between the eyes�, it does not to refer to the actual eyes, but rather to the optic nerves that allow the eyes the ability to see and process information through their neural connections to the brain.
As Rufus of Ephesus discovered, described and named in the year 100 CE � but the Torah (can you say G-d?) apparently knew about over 1400 years before him � the optic nerves from both eyes meet and cross at the �optic chiasm�. The optic chiasm is situated at exactly the same place where the head-tefillin are to be worn. Thus the Tefillin is placed on the top of the head at the crossing point of the optic nerves, i.e. �between the eyes�.
I don�t know about you people, but I find all this stuff about Tefillin and the optic chiasm to be absolutely amazing!! I hope you enjoyed it as well.
[Sources: 30 Days to Bar Mitzvah: An Illuminating Guide to the Mitzvah of Tefillin by Rabbi Dovid A. Gross; Judaica Press 2011]
http://www.torchweb.org/torah_detail.php?id=375