399. The Color of the Straps

Tefillin, Mezuzah v’Sefer Torah 3:13

One passes the straps through the handles of the tefillin, leaving enough room for his head, then ties a square knot that resembles the Hebrew letter daled. Every Torah scholar should learn how to tie this knot, which cannot be described in writing. It must be seen to be understood. The straps of the arm tefillin must be tied with a knot that resembles the Hebrew letter yud. This knot should allow the strap to pass through it so that it can be made tighter or looser when tying the tefillin on the arm.

Tefillin, Mezuzah v’Sefer Torah 3:14

The outside of the straps of both the head tefillin and the arm tefillin must be black; this is a law that was communicated to Moses at Sinai. The side that faces the inside could even be green or white, though one should not make it red because this will be embarrassing if his straps should get turned over. The back of the straps should be the same color as the boxes - if it’s green, then green, if white, then white. It is best for tefillin to be entirely black.