Mishnah Shabbat 21

¹A man may pick up his son while he has a stone in his hand or a basket with a stone in it. And one may carry impure terumah together with pure [terumah] or with non-sacred produce. Rabbi Judah said: one may also remove the mixture [of terumah in non-sacred produce] when one [part is neutralized] in a hundred [parts]. ²If a stone is on the mouth of a cask [of wine], one tilts it to its side and it falls off. If it [the cask] is [standing] among [other] casks, he lifts it up, tilts it on its side, and it falls off. If money is lying on a cushion, one shakes the cushion, and it falls off. If snot is on it, one wipes it off with a rag; If it is on leather, one pours water over it until it disappears. ³Bet Shammai says: one may remove bones and nutshells from the table; But Beth Hillel says: one must remove the whole board and shake it off. One may remove from the table crumbs less than the size of an olive and the husks of beans and lentils, because they are food for animals. A sponge, if it has a handle, one may wipe [the board] with it; If not, one may not wipe [the board] with it. The sages say: in either case it may be handled on Shabbat and it is not susceptible to defilement.