Question
Many people have the custom to spit when reciting the words “Sheheim Mishtachavim…” during Aleinu. After spitting on the floor, may one rub the saliva into the floor with his shoe as is commonly done during the week, or does this present a Shabbos problem? Does it matter whether the floor is tiled or earthen?
Answer
Yes. In a synagogue with a tiled floor, which is the case in virtually all modern shuls, one may rub the saliva into the floor just as he does during the week.
However, if one spits onto an earth floor, then he may not rub the saliva into the ground. Rather, he should simply step on it until it disappears without deliberately rubbing it into the earth.
Explanation
The General Concern of Rubbing Saliva on Shabbos: The Gemara and Poskim discuss whether one may rub saliva into the ground on Shabbos. The concern is that by rubbing saliva into an earth floor, one smoothens and levels the surface of the ground, which is connected to the prohibition of building (Boneh). Accordingly, rubbing saliva into dirt or earth is generally forbidden. For this reason, one may not intentionally grind saliva into an earth floor with his foot.
Walking Over Saliva: The Poskim distinguish between intentionally rubbing saliva and merely stepping on it while walking. If the saliva happens to be in one’s path, one may walk over it. The Poskim explain that since the person’s intent is to continue walking and not to improve the ground, Chazal were lenient, especially since saliva is considered repulsive and people naturally wish to cover it. Nevertheless, one should not specifically walk over to the saliva in order to rub it into an earth floor.
What About Tiled Floors? On a tiled floor, the issue is much less severe because there is no actual ground being leveled. Nonetheless, historically there was a debate whether Chazal prohibited rubbing saliva even on a tiled floor lest one come to do so on an earth floor. The Mishnah Berurah records that Ashkenazic practice follows the stringent view. However, the Ketzos Hashulchan and other Poskim note a crucial point. The original decree was enacted during times when many homes contained earth floors. Today, the overwhelming majority of homes and buildings have tiled, stone, wood, or similar finished flooring. Accordingly, these Poskim rule that the concern underlying the decree no longer applies in the same way. Therefore, they conclude that one may rub saliva into tiled floors.
The Practical Application to Aleinu: Based on the above, the Ketzos Hashulchan, Az Nidberu, and Piskei Teshuvos write that when one spits during Aleinu in a synagogue that has a tiled floor, he may rub the saliva into the floor in the normal fashion. The reasoning is straightforward: since today most houses and buildings have tiled floors, the decree against tiled floors does not apply according to these authorities.
One who wishes to be stringent may simply step on the saliva until it disappears without actively rubbing it.
Practical Summary
| Situation | Ruling |
| Spitting during Aleinu on a tiled shul floor | May rub it into the floor |
| Spitting during Aleinu on an earth floor | May not rub it into the ground |
| Saliva in one’s path on an earth floor | May step on it while walking |
| Standing on saliva without rubbing | Permitted |
| One who wishes to be stringent on a tiled floor | May simply step on it until it disappears |
Sources
The prohibition against rubbing saliva into an earth floor because of smoothing the ground: Michaber 316:11; Shabbos 121b
The allowance to step on saliva while walking when it is in one’s path: Magen Avraham 316:25; Mishnah Berurah 316:51; Ketzos Hashulchan 146:30
The debate regarding rubbing saliva on tiled floors: Mishnah Berurah 316:49; Ketzos Hashulchan 146:65
The ruling that where most houses have tiled floors one may rub saliva on tiled and wooden floors: Ketzos Hashulchan 146:65; Az Nidberu 6:24; Piskei Teshuvos 316:7; See also 337 Biur Halacha “Veyeish Machmirim”
The practical ruling regarding spitting during Aleinu in shul: Ketzos Hashulchan 146:65; Az Nidberu 6:24; Piskei Teshuvos 316:7; See also 337 Biur Halacha “Veyeish Machmirim”