Question: May I pray when my child is walking around the house in a dirty diaper?
Answer: We derive from the verse in the Torah, “And your camp shall be holy”, that one may not recite words of Torah, pray, or perform any acts of holiness (for instance donning Tefillin) in the restroom or any other unclean place. Similarly, one may not pray, speak, or think words of Torah when there is a foul object in front of him, such as human waste, a chicken coop, a corral of goats, and the like, as the Torah states, “And your camp shall be holy.” If one mistakenly prayed or recited a blessing when there was human excrement in front of him, one has not fulfilled one’s obligation and one must pray again. Even if the waste does not give off a bad odor, if one prayed while facing the waste, one must repeat one’s prayers elsewhere.
Furthermore, one may not pray or speak words of Torah in a place where there is an offensive odor, such as in the presence of a sewer leak, in a place where there are fields fertilized with animal manure, or in the presence of a child with a dirty diaper. Even if the specific individual wishing to pray does not smell the offensive odor, as long as other people do, he may not pray there. The Magen Avraham writes that even if the source of the bad odor was cleaned up and removed, if the odor still lingers, one may not pray there until it passes completely. Thus, even if a baby’s diaper was changed, if the offensive odor still lingers in the air, one may not pray there.
We must now address the proper procedure for a congregation wanting to pray while there is a sewer leak in a neighboring street or a woman wanting to pray at home after removing a dirty diaper from the area but the odor still lingers. First and foremost, if the source of the offensive odor is still in the vicinity, for instance, if there is actual waste in the area, it is surely prohibited to pray there. We are only addressing a situation where the source of the odor was removed and only the odor itself lingers.
We must first begin by explaining another Halacha: During the times of the Bet Hamikdash, the Kohanim would perform the bulk of the services in the Temple, such as the offering sacrifices, burning the Ketoret (incense), and the like. The Kohanim who served in the Bet Hamikdash could not be blemished and if a blemished Kohen performed a service, the service was invalid. One of the blemishes that would invalidate a Kohen from service in the Bet Hamikdash was a Kohen who would sweat profusely and thus let off an offensive odor or a Kohen who had offensive breath. The Rambam writes that a Kohen who exudes an offensive odor may wash himself and rub his skin with pleasant fragrances and his service will subsequently be valid. Similarly, a Kohen with bad breath may chew ginger or spearmint to freshen his breath and his service would thus be valid. We see clearly that even though without the external fresheners there would be an offensive odor given off, the pleasant scent would nevertheless offsets the bad odor and the Kohen’s service will be valid.
We can derive from here a similar Halacha regarding our situation: If there is a foul odor in the synagogue or at home, one may offset it with another scent and then the original odor will no longer pose a problem. Thus, the Poskim write that one may burn a garment in the synagogue so that the smell of the burning material will offset the unpleasant odor and it will subsequently be permissible to pray there. Similarly, one may spray an air freshener in the synagogue to counteract the previous offensive odor and the congregation will thus be permitted to pray there.
It happened once approximately five years ago in the synagogue of Maran zt”l that the time for Mincha arrived and a terrible odor engulfed the entire neighborhood due to a burst sewage pipe, thus preventing the commencement of Mincha prayers. Maran zt”l, in his classical way of bringing the words of the Poskim to life, immediately instructed his personal driver to bring a towel from the house and to burn it. After it became clear that it would be more practical to just spray some air freshener instead, Maran zt”l approved and instructed them to do so. Copious amounts of air freshener were sprayed until the offensive odor was offset, and Mincha prayers commenced.