Q&A from the Bais HaVaad Halacha Hotline

Beyond the Scope

December 7, 2022

Q May I use mouthwash or whiskey on Shabbos to soothe the pain of a canker sore?

A Chazal forbade medical treatments (refuah) on Shabbos lest one inadvertently transgress the melacha de’Oreisa of grinding while preparing medicine (S.A. O.C 328:1). Even a nonmedical remedy, like rinsing the mouth, is forbidden, as the Mishnah teaches (Shabbos 111a): “One whose teeth hurt may not sip vinegar through them (to soothe the pain).” Rinsing your mouth to salve canker sores is therefore forbidden.

But that is only if the liquid is spat out. If it is swallowed afterward, it is permitted, because the refuah intent is not evident (S.A. ibid. 32). But this varies by time and place, and since today people don’t generally drink vinegar, it is forbidden even if it will be swallowed (see M.B. ibid. 105). But whiskey is permitted even today if it will be swallowed.

Still, one should not slosh the whiskey around in his mouth, but immediately swallow it, so the refuah objective remains unnoticeable (M.B. ibid. 101). If one is significantly irritated and will not be soothed without sloshing, he may be lenient with whiskey (ibid. 102).

Mouthwash, in this respect, is far more lenient, because it is normal for people to use it for non-remedy purposes. The Mishnah (Shabbos 109b) permits eating foods for healing purposes, because the act of eating is not indicative of medical treatment (Shabbos 109b). One may even spit out the mouthwash afterward, as that is the normal practice in its usual, non-remedy use. It is akin to eating foods for medical purposes.

The prohibition of refuah on Shabbos does not apply when one is strongly affected by the pain. This might happen if one has several sores and is in too much discomfort to go about his day. In that case, refuah is permitted even when it is evident (M.B. ibid. 100), and one may even instruct a non-Jew to perform a melacha (S.A. ibid. 17).