Within the Shema we find two references to the mitzvah of tefillin which you, as a new bar mitzvah, are now required to observe. In both the first portion of the Shema, which was read today, and the second portion, which we will read next week, Hashem commands Bnei Yisrael to “bind them as a sign upon your arm, and let them be ‘totafot’ between your eyes.” That Hashem saw fit to mention this mitzvah twice in the Shema suggests that this mitzvah carries with it a special message, a message which bears upon all the other mitzvoth that
you are now required to observe.