Responsa for Shabbat 281:20
א"ר אבהו א"ר אלעזר אמר ר' ינאי מגררין מנעל חדש אבל לא ישן
four cubits in a <i>karmelith</i>.<span class="x" onmousemove="('comment',' V. Glos. ');"><sup>17</sup></span> If so, when he enters<span class="x" onmousemove="('comment',' Lit., 'goes down'. ');"><sup>18</sup></span> too, his force propels the water four cubits,<span class="x" onmousemove="('comment',' His weight makes the water spurt that distance. ');"><sup>19</sup></span> which is forbidden? — They did not prohibit one's force in a <i>karmelith</i>. Abaye — others state, Rab Judah — said: One may scrape off the clay from his foot on to the ground, but not on to a wall. Said Raba, Why not on to a wall? because It looks like building?<span class="x" onmousemove="('comment',' Sc. the addition of clay to the wall. ');"><sup>20</sup></span> but it is ignorant building?<span class="x" onmousemove="('comment',' Lit., 'a field labourer'. I.e., surely none but the ignorant would think of building in such a manner. ');"><sup>21</sup></span> Rather said Raba: He may scrape it off on to a wall but not on to the ground, lest he come to level holes. It was stated, Mar son of Rabina said: Both are forbidden; R. Papa said: Both are permitted. According to Mar son of Rabina, whereon shall he scrape it? He scrapes it on a plank.<span class="x" onmousemove="('comment',' Lying on the ground. ');"><sup>22</sup></span> Raba said: A man should not sit on the top of a stake,<span class="x" onmousemove="('comment',' At the entrance to an alley. whereby carrying therein is permitted; v. p. 30, n. 2. ');"><sup>23</sup></span> lest an article roll away from him<span class="x" onmousemove="('comment',' 'Without the entrance, where it is public ground. ');"><sup>24</sup></span> and he come to fetch it. Raba also said: One must not bend sideways a cask [which is standing] on the ground,<span class="x" onmousemove="('comment',' Text as emended by BaH. ');"><sup>25</sup></span> lest he come to level hollows. Raba also said: One must not squeeze a cloth stopper into the mouth of a jug, lest he come to wring [it] out. R. Kahana said: As for the clay [mire] on one's garment, he may rub off from the inside but not from the outside.<span class="x" onmousemove="('comment',' In the latter case he looks as though he desires to wash the garment, though it is not actual washing. ');"><sup>26</sup></span> An objection is raised: One may scrape off the clay from his shoes with the back of a knife, and that which is on one's garment he may scrape off with [even]<span class="x" onmousemove="('comment',' So Wilna Gaon. ');"><sup>27</sup></span> his finger nail, providing that he does not rub it. Surely that means that he must not rub it at all? — No: he must not rub it from the outside but only from the inside. R. Abbahu said in R. Eleazar's name in R. Jannai's name: A new shoe may be scraped, but not an old one.
Teshuvot Maharam
A. He should fasten a board beneath the seat (within not more than three tefahim below the latrine walls) so that the feces first fall on the board and then into the ditch. Should the board break on the Sabbath, he would still be permitted to use the latrine on that day.
SOURCES: Cr. 178, 179; Pr. 96; L. 349; Mord. Shabb. 376; Hag. Mord. Shabb. 461; Tashbetz 38; Hag. Maim., Shabbat 15, 4; Kol Bo 31 (p. 34a). Cf. Terumat Hadeshen 66.
Teshuvot Maharam
A. He should fasten a board beneath the seat (within not more than three tefahim below the latrine walls) so that the feces first fall on the board and then into the ditch. Should the board break on the Sabbath, he would still be permitted to use the latrine on that day.
SOURCES: Cr. 178, 179; Pr. 96; L. 349; Mord. Shabb. 376; Hag. Mord. Shabb. 461; Tashbetz 38; Hag. Maim., Shabbat 15, 4; Kol Bo 31 (p. 34a). Cf. Terumat Hadeshen 66.