In some communities, it is customary for the father to wear Tefillin during his son’s Berit. Is this a proper practice?
While all agree that it is proper to wear a Tallit during the Berit, out of respect for the Misva, there is some discussion regarding the propriety of wearing Tefillin during a Berit.
One objection to this practice was raised by a Rabbi cited by the Hida (Rav Haim Yosef David Azulai, 1724-1806), in his work Mar’it Ha’ayin. This Rabbi contended that it should be forbidden to wear Tefillin during a Berit, for the same reason Halacha forbids wearing Tefillin on Shabbat. Our Sages teach that Tefillin is described as an "Ot" ("sign") of our connection with G-d, just as Shabbat is. If we wear Tefillin on Shabbat, we give the impression that Shabbat itself is insufficient as an "Ot," thus necessitating Tefillin, and for this reason, the Sages forbade wearing Tefillin on Shabbat, in order to preserve the honor of Shabbat. Berit Mila, too, is described as an "Ot" of our covenant with Hashem, and thus, seemingly, just as it is forbidden to wear Tefillin on Shabbat, it should be forbidden to wear Tefillin at a Berit, as this would imply that the Berit itself is not a clear enough sign of our special bond with the Almighty.
The Hida strongly rejects this line of reasoning. He notes that if one wears Tefillin on Shabbat, he himself is showing two signs of the Berit – he is observing Shabbat, and he is wearing Tefillin. At a Berit, however, the circumcision is being performed on the infant, not on the father, and thus the father’s wearing Tefillin does not imply anything about the "sign" of circumcision. Moreover, the Hida argues, according to this Rabbi’s logic, we should never wear Tefillin, because we have the sign of the Berit on our bodies at all times. Just as we observe Shabbat as a "sign" of the Berit despite our already having such a sign in the form of the Berit Mila, there is no problem at all wearing Tefillin during the circumcision of one’s child.
Nevertheless, the general practice among Sepharadim is not to wear Tefillin during a Berit. Additionally, Hacham Baruch Ben-Haim (1921-2005) discouraged fathers from keeping their Tefillin on after Shaharit until the Berit, because usually, when Beritot are performed after Shaharit, there is a delay between the conclusion of Shaharit and the Berit, during which time people mingle and socialize. It would be disrespectful to the Tefillin to socialize while wearing them, and so Hacham Baruch felt it would be best to remove one’s Tefillin after Shaharit, rather than keep them on for the Berit.
It should be noted that if a Berit is being performed on Rosh Hodesh, one should not put his Tefillin on for the Berit. After we remove our Tefillin before Musaf on Rosh Hodesh, they should not be put on again, and so on Rosh Hodesh, it is improper to put on Tefillin for a Berit.
On all other occasions, however, it would be permissible to put one’s Tefillin on for a Berit, or to keep them on after Shaharit if the Berit is being performed immediately after the conclusion of the prayer service, such that the Tefillin will not be disrespected in the interim. As mentioned, however, the prevalent practice in our community is not to wear Tefillin at a Berit.
It should be noted that generally speaking, Mohalim do not wear Tefillin while performing the Berit, for the simple reason that the straps might interfere with their work. It goes without saying that a Mohel’s very highest priority when performing a Berit is to ensure that it is done properly, and thus Mohalim generally do not wear Tefillin at a Berit, as the Tefillin might get in the way. Many Mohalim do not wear a Tallit while performing a Berit, either, for the same reason, as the Sisit strings might interfere with their work.
Summary: In some communities, it is customary for a father to wear Tefillin at his son’s Berit, though this is not the common practice among Sephardic communities. Regardless, one should not wear Tefillin for a Berit on Rosh Hodesh, as it is improper to put Tefillin back on after removing them before Musaf on Rosh Hodesh. Additionally, one should not keep on his Tefillin after Shaharit if there is a delay before the Berit during which time he will be mingling, as this would be disrespectful to the Tefillin.