Double Sided Retzuos
Question: My tefillin straps were wearing down and had become narrow and stretched in places, so my Rav advised me to buy new ones. The sofer offered a choice between retzuos that are black on one side or both sides. I have always used one-sided retzuos . Is there any advantage to having them black on both sides? Answer: The Gemara (Menachos 35a) teaches that it is a halacha given to Moshe at Sinai that the outward facing side of the retzuos must be black, while the reverse side may be any colour except red. Rambam (Tefillin 3:14) adds that having the retzuos entirely black is considered an enhancement. Nonetheless, the Shulchan Aruch (OC 33:3) rules that only the outer side must be black. The Rema (Darkei Moshe OC 33:2), quoting the Ohr Zarua, notes that since it became customary to make the batim black, there is reason to suggest that the retzuos should also be black on both sides. However, he concludes that this was not adopted in practice, and the prevailing custom is...