Commentary for Shabbat 21:3
בֵּית שַׁמַּאי אוֹמְרִים, מַגְבִּיהִין מִן הַשֻּׁלְחָן עֲצָמוֹת וּקְלִפִּין. וּבֵית הִלֵּל אוֹמְרִים, נוֹטֵל אֶת הַטַּבְלָה כֻלָּהּ וּמְנַעֲרָהּ. מַעֲבִירִין מִלִּפְנֵי הַשֻּׁלְחָן פֵּרוּרִין פָּחוֹת מִכַּזַּיִת וְשֵׂעָר שֶׁל אֲפוּנִין וְשֵׂעָר שֶׁל עֲדָשִׁים, מִפְּנֵי שֶׁהוּא מַאֲכַל בְּהֵמָה. סְפוֹג, אִם יֶשׁ לוֹ עוֹר בֵּית אֲחִיזָה, מְקַנְּחִין בּוֹ, וְאִם לָאו, אֵין מְקַנְּחִין בּוֹ. וַחֲכָמִים אוֹמְרִים בֵּין כָּךְ וּבֵין כָּךְ, נִטָּל בְּשַׁבָּת, וְאֵינוֹ מְקַבֵּל טֻמְאָה:
Beth Shammai say: It is permitted to lift bones and shells from the table (on Shabbath). Beth Hillel say: He takes the entire tablecloth and shakes it out. [The gemara explains that we do not rely upon our Mishnah as stated, but reverse it, viz.: "Beth Hillel say: It is permitted … and Beth Shammai say: He takes the entire tablecloth, etc.", for it (the tablecloth) has the status of a (movable) article. But he may not take the bones and the shells with his hands. For Beth Hillel hold with R. Shimon; and Beth Shammai, with R. Yehudah. However, Beth Hillel permit it only with bones and shells that are fit to be eaten by animals though not fit to be eaten by men; but if they are not fit to be eaten by animals either, Beth Hillel concur that it is forbidden to handle them, for in such an instance, even R. Shimon concurs.] It is permitted to remove crumbs [even] less than the size of an olive from the table, and bean shells, and lentil shells, for they are animal food. A sponge — if it has a leather handle, one may clean with it; if not, one may not clean with it. [For when he holds it, it is squeezed by his fingers, and it is inevitable (that water be squeezed out), in which instance R. Shimon concedes (that it is forbidden)]. And the sages say: In either case, [whether or not it has a handle], it may be taken on Shabbath [when it is dry], and it does not acquire uncleanliness, [for it is neither a wooden vessel, nor cloth, nor sack, nor metal].
Bartenura on Mishnah Shabbat
English Explanation of Mishnah Shabbat
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.
This mishnah deals with clearing the table at the end of a meal on Shabbat.
Section one: Bet Shammai does not hold that the bones and nutshells left over on the table after the meal are muktzeh even though they have no use. Hence one may remove them. Bet Hillel disagrees and holds that these are muktzeh. Hence, if she wishes to remove them, she must remove the board from the table (a sort of personal tray placed in front of one or several diners) and shake it off. In the Talmud they bring a source according to which these two opinions should be reversed, Bet Hillel holding the more lenient opinion and Bet Shammai the stricter one.
Section two: Animal food is not muktzeh. Since crumbs and husks of beans and lentils may be used for animal food, they are not muktzeh and it is permitted to remove them from the table on Shabbat.
Section three: This section discusses the problem of sponges. Squeezing water or liquids out of something is prohibited. Its prohibition is derived from the prohibited labor of “laundering”, since squeezing water out of clothes is part of the laundering process. One can’t use a sponge that does not have a handle because by doing so one might squeeze water from the sponge.
The sages say that whether or not it has a handle it may be carried on Shabbat because it is a vessel and all vessels may be carried on Shabbat. However, it is not the type of vessel that can receive impurity.
Some manuscripts read differently in the concluding clause. Some read, “and the sages say: in any case he may use it for wiping.” According to this version, the sages disagree with the previous opinion, according to which wiping with a sponge without a handle is forbidden. Other versions skip the words “and the sages say” and rather read the final point as a point of agreement between all. All agree that even though you can’t use the sponge to wipe things, it still may be carried.