788. Leveling the Ground
Shabbos 21:2
If a person levels holes in the ground, he is liable for plowing. For this reason, one may not defecate in a fallow field, out of concern that he may come to level the earth. If a person empties out a storeroom on Shabbos because he needs the room for the purposes of a mitzvah, such as to house guests or for use as a study hall, he should not empty the room completely out of concern that he may come to level the floor. If a person has mud on his feet, he may clean it off on a wall or a beam but not on the ground, again out of concern that he may come to level the holes in the ground. One may not spit on the ground and rub it with his foot out of concern that he may level the earth. It is permitted to step on spit on the ground while walking as long as one has no specific intention to do so.
Shabbos 21:3
Women who play with things like nuts and almonds may not do so on Shabbos out of concern that they may come to level the ground. It is prohibited to sweep the ground for fear of leveling it unless it is paved with stone. One may sprinkle water on the ground; there is no concern that this will cause him level the ground as such is not his intention. One may not, however, apply oil even to a paved floor, nor may one blow dust off, nor wash it. This is the case on yom tov and all the more so on Shabbos. These things were prohibited in order to prevent one from acting according to his normal weekday routine, which could then lead to leveling the holes in an unpaved location.