Q&A from the Bais HaVaad Halacha Hotline

Clean Hands Doctrine

March 14, 2024

Q If I have to leave the table during a meal, must I repeat netilas yadayim upon returning?

A Following a hesech hada’as (mental disengagement), one must wash anew. If you leave the table and get involved in something else for an extended period of time—over an hour—that qualifies as a hesech hada’as (Shulchan Aruch O.C. 170:1). In this case, netilas yadayim should be repeated with a bracha. Though there may not have been a hesech hada’as from eating—as you intended to return and eat, and therefore hamotzi is not repeated—there was a hesech hada’as from your hands (Mishnah Brurah 164:13). Similarly, if you take a nap, a new netilah with a bracha is required (M.B. 178:48).

If you touch a part of the body that is normally covered (makom mechuseh) or scratch your head, netilah is required because of the sweatiness of those areas (O.C. 164:2). Many poskim debate whether a bracha is recited on the second netilah. The Mishnah Brurah concludes that it is not, unless a makom metunaf (soiled area) was touched. Touching a sweaty undergarment is akin to touching a makom mechuseh (Mishnah Brurah ibid. 10).

If you are unsure whether a makom metunaf was touched or just a makom mechuseh, a bracha may be recited, as we may rely on the Chazon Ish’s view that touching any makom mechuseh requires a new bracha (Chazon Ish O.C. 25:9).

Poskim debate the case of one who touched a makom mechuseh that was recently washed. Some say netilah is not needed, because the reason doesn’t apply (Kaf Hachaim 4:85); others say that the halacha applies even though the reason does not (Eishel Avraham 4).

If you use the bathroom, netilah with a bracha is required, as the hands touch unclean areas. If only one hand did so, only that hand need be washed (ibid.). If neither hand did, no netilah is required (O.C. 170:1).

If you change a baby’s dirty diaper, netilas yadayim must be redone with a bracha. If your hands are soiled with mud or dirt, netilah is not necessary.