2. Question: Why can we wear tefillin during a bris but not on Shabbos or yom tov? Background:
A. There are 3 things that are called signs and they can’t actively overlap with each other besides bris, the 3 are bris, tefillin, and shabbos/yom tov.
B. The problem with overlapping signs is that you are degrading one sign when having the other that is why one does not wear tefillin on Shabbos and yom tov but if so then he shouldn’t wear it when a bris is being performed?
Answer: Rav Moshe Feinstein answers (Igros Moshe Orach Chaim volume 4 question 101) the sign isn’t the act of giving the bris but the fact that one has a bris therefore the father can give his son a bris with tefillin on (to give a reason for the act of the bris, and to show that it’s an action of giving over the sign.) Where as Shabbos and Yom tov is the sign itself so to wear the tefillin during that day cheapens the day. [/exapnd]