Some congregations hang American and Israeli flags inside the sanctuary of the synagogue. Is this practice permissible, or something which ought to be discontinued? Generally, it is forbidden to bring into a synagogue mundane items that do not somehow contribute or relate to the synagogue’s role as a place of prayer and holiness. At first glance, then, we might conclude that flags should not be brought into the synagogue.
Rav Moshe Feinstein (Russia-New York, 1895-1986) addressed this question and ruled that congregations who have adopted this practice have a Halachic basis on which to rely. In his view, if flags have already been hung in the synagogue, community members should not object or initiate a campaign to have them removed if this would cause strife among the community. Since there is basis to allow hanging flags in the synagogue, campaigning for their removal is not worth the price of causing friction in the community.
Rav Moshe’s ambivalence toward hanging flags in the synagogue should alert us to the importance of maintaining a proper aura of reverence and sanctity in our Bateh Kenesset. The fact that the question was raised, and that Rav Moshe allowed flags only in the interest of maintaining peace in the congregation, reminds us how careful we must be in determining what we allow in the synagogue. It goes without saying that one should not bring a cellular phone into the synagogue before turning it off. (In cases where one must be reachable, such as a man whose wife is due to give birth, one may leave the phone on vibrator mode.) Bringing an active phone into the synagogue, which could ring at any moment, is terribly disrespectful to the synagogue. There are some congregations that have installed scramblers in the synagogue so that all cellular phones in and in the vicinity of the synagogue cannot work. This is certainly a measure that congregations might want to consider in order to preserve the reverence and sanctity that our Bateh Kenesset deserve.
Summary: As a general rule, it is forbidden to bring mundane articles into a synagogue, though communities that hang flags in the synagogue have a Halachic basis on which to rely. Certainly, however, we must exercise care regarding objects that we allow in the synagogue, and cellular phones should not be brought into the synagogue unless they are turned off (or, in cases of need, switched to vibrator mode).