Why Does Chabad Have Such Large Tefillin?

Ask the Rov: Why is the minhag in Chabad to have such large tefillin?

By Rabbi Chaim Hillel Raskin – Rov of Anash in Petach Tikvah

Chazal say that there is room on the head for two pairs of head-tefillin, and there is room on the bicep for two pairs of arm-tefillin.¹ This implies there is a minimum size of the tefillin’s base (titura), for otherwise, there could be room for more than two pairs.²

Tosfos quotes a midrash that the bayis of the head- tefillin should l’chatchila be two by two etzbaos (four by four cm), though smaller ones would still be kosher. If there is space for exactly two such tefillin, one should not make tefillin larger than 4 by 4 etzbaos (the size of two such pairs).

Some Rishonim hold that the titura counts toward the size, but Shimusha Rabba holds that the bayis itself should contain the shiur. According to this approach, although there is room on the head for two batim, they wouldn’t actually fit due to the protruding titura.

While some poskim rule that the shiur includes the titura, and the actual bayis can be smaller,³ the Alter Rebbe writes to be concerned for the stricter view, though he notes that the common custom was not so.⁴ Minhag Chabad is to make the bayis itself two by two etzbaos,⁵ hence the reason for larger tefillin.

Though the arm-tefillin could technically be one etzba,⁶ it is considered hidur mitzvah if both are the same size. For a petite bar mitzvah bochur with a small arm, some prefer to have smaller arm-tefillin so that it fits in the correct spot, thought it isn’t the widespread practice.

Regarding the height of the tefillin, the Rama writes that there is no problem to make them taller than their width. Yet, it is considered more mehudar for the height to be equal to the length and width, and that is the minhag Chabad.⁷

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From The Weekly Farbrengen by Merkaz Anash