Reference for Shabbat 285:7

מעבירין מלפני השלחן פירורין: מסייע ליה לר' יוחנן דאמר רבי יוחנן פירורין שאין בהן כזית אסור לאבדן ביד:

ONE MAY REMOVE FROM THE TABLE CRUMBS LESS THAN THE SIZE OF AN OLIVE AND THE PANICLES OF BEANS AND LENTILS, BECAUSE THEY ARE FOOD FOR ANIMALS. AS FOR A SPONGE, IF IT HAS A LEATHERN HANDLE, ONE MAY WIPE [THE BOARD] WITH IT; IF NOT, ONE MAY NOT WIPE [THE BOARD] WITH IT.<span class="x" onmousemove="('comment',' For fear of wringing out the absorbed moisture. ');">⁷</span>

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