Q. Why do we remove tefillin on Rosh Chodesh before davening Musaf?

A. There are a number of reasons for this tradition:

Shulchan Aruch (O.H. 25: 13) writes that it is tradition to remove our tefillin before davening Musaf on Rosh Chodesh. Mishna Berura (59) quotes Eliahu Rabah one should remove them after ending Uva Letzion when we pray for Hashem helping us to keep his mitzvos and should not wait until finishing Kaddish so not to separate between Kaddish and the Amida.

The Aruch Hashulchan (25:28) writes that many gedolim objected to the latter statement of the Rema. Why should one not wear tefillin for Musaf if Keser is not said. Nonetheless, the Aruch Hashulchan maintains that this custom was universally accepted on the basis of Kabbilistic considerations, and it should not be challenged.

The Levush (423:4) offers another explanation. We remove tefillin before Musaf, because tefillin is referred to in Chumash Shemos (13:9.88) as an “os” (sign) and Yom Tov is referred to as an “os.” It is inappropriate to wear tefillin on Yom Tov since this detracts from the “os” of Yom Tov.

Although Rosh Chodesh does not have the same sanctity as Yom Tov, and is not referred to as an “os,” the korbanos of Rosh Chodesh are listed together with the other holidays. Therefore, before Musaf, in which we will mention the korbanos brought on Rosh Chodesh, it is appropriate to remove one’s tefillin. See next questions.

Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu and Horav Kalman Ochs Shlit’a.