Tefillin Mirror

Question: I see many people use a mirror to ensure that their tefillin shel rosh is placed exactly in the middle of one’s head. Is this necessary?

Answer: The Shulchan Aruch (OC 27:10) writes that one must ensure to place one’s tefillin shel rosh in the middle of one’s head. The Mishna Berura (27:36) notes that one does not fulfil the mitzva according to some acharonim if one’s tefillin are not in the middle, adding that larger tefillin can be problematic.

The Shulchan Aruch (YD 156:2) writes that men should not look in a mirror unless they need to do so for medical reasons, etc. Nonetheless, the Rema writes that where it is common for men to do so, it poses no issue.

Nonetheless, R’ Chaim Sanzer (Divrei Chaim OC 2:6) demonstrates that the tefillin do not need to be exactly in the middle and writes that using a mirror to position one’s tefillin is considered uncouth. R’ Menashe Klein (Mishne Halachos 5:8; 11:29-30) notes that the Brisker Rav was accustomed to using one. Nonetheless, he writes that for thousands of years, men wore tefillin without using a mirror, and it is ideal not to use one. R’ Eliezer Waldenberg (Tzitz Eliezer 12:6:2) concurs, adding that, if necessary, one may look into a dim reflection of a window, etc.

Sefer Halichos Shlomo (Tefilla 4:n108) notes that R’ Shlomo Zalman Auerbach used a mirror to position his tefillin later in life. Likewise, the Dirshu Mishna Berura (27:n42) quotes R' Yosef Shalom Elyashiv who maintained that as men do use mirrors nowadays, it is appropriate to use one.

In conclusion, there are different opinions regarding using a mirror to straighten one’s tefillin. Some Chassidishe poskim frown upon using one while others are encouraging.