I'm very interested in Tefillin and I was wondering if anyone knew of any traditional sources which are either dedicated to or devote serious attention to the meaning of the mitzvah & it's status as a spiritual practice. Not just a hilchot tefillin book, I've got that. I've also read Aryeh Kaplan's book, which is pretty good but the style of which leaves something to be desired. Anyone know of a sefer or two of this kind?
I highly recommend this sefer on teffilin alot of interesting information with deep concepts of teffilin.The Inside story of teffilin by Rabbi Emanuel http://www.menuchapublishers.com/tefillin-the-inside-story.html