The Magen Avrohom in the Siman לח׳ Says that if someone is not wearing a shirt and his heart is revealed ussor for him to put on Tefilin The Levushai serud says because tefilin is domi letfillah if it’s so my question is how come everything else Medina of the Gemara is mutar meaning Medina degemara מבואות מטונפות is mutar for tefilin and ussor for tefillah so how does it reconcile with the levushai serud הנל
Thank you for your question.
Here is a quote of the the Levushei Srad דאע”ג דבסימן צ”א וסימן ע”ד מבואר דבקריאת שמע מותר, רק בתפילה אסור דהוא מדבר בפני המלך, תפילין נמי כרפילה דמי שחתום בחותם המלך, וצריכין אימה ויראה כמו בתפילה”. What he is saying is that since the Tefillin has Hashem’s name on it, we have to treat it with respect and be dressed properly while wearing the tefillin, which has Hashem’s name on it. He does not mean to say that it is compared to all other Hilchos Tefillah. As a side point, although the Levushei Serad says this, if a person is in a situation that they can only put on tefillin without a shirt, the tefillin should still be worn. This is because, this is idea is not meakev for the tefillin, rather an idea or respect, but if it isn’t possible on may still wear them. (See Pri Megadim Eshel Avrohom 38-1, that b’dieved it is permitted to make the bracha on the tefillin. Also see 38-1 in the Mishna Berura of Ahavat Shalom that says this.)