Take the 2-minute tour ×  I've heard and seen religious Jews
painting the backs of the tefillin straps black, and they claim
a kabbalistic reason somewhere in the Schulchan Auruch. Does
anyone know anything about this, the reason, and source?
share|improve this question Welcome to Mi Yodeya Sam! Nice
question. –  Bruce James Dec 24 '13 at 0:12  1 Answer 1  up vote
3 down vote accepted  There are opinions that this makes the
Tefillin a more beautiful Mitzvah. Although the Arizal may be
one of them, the Rambam, the Or Zarua and others who are not
regarded as kabbalistic in their rulings also rule this way.
The general custom is to not do this, but as you noted, there
are those who follow those opinions. Nobody puts it as a
requirement (except perhaps some Kabbalists, depending on their
understanding of the Arizal), but rather as a Hiddur Mitzvah.
share|improve this answer  Your Answer