Responsa for Yevamot 209:11
אבל אגיד לך הרשום בכתב אמת וכי יש כתב שאינו אמת
was merely shaking him off. When, however, he went out he carefully considered the point and discovered that it was taught: Whether drawing off the shoe preceded the spitting or whether spitting preceded the drawing off, the action performed is valid.<span class="x" onmousemove="('comment',' Cf. infra 106b, Sanh. 49b. ');"><sup>28</sup></span> Levi once went out [to visit] the country towns,<span class="x" onmousemove="('comment',' In the course of a lecture tour. According to the Palestinian Talmud and the Midrash Rabbah, Levi was sent by R. Judah the Prince to take up an appointment as teacher and judge in a provincial town. In his excitement and pride he grew so bewildered that he was unable to answer the following three questions. ');"><sup>29</sup></span> when he was asked: 'May a woman whose hand was amputated perform <i>halizah</i>?<span class="x" onmousemove="('comment',' With her teeth. ');"><sup>30</sup></span>
Teshuvot Maharam
A. Bediabad, in this case, means after the rite was performed. Nevertheless, the aforementioned performance of the rite is invalid, for a different reason: the shoe used was sewed with flaxen thread and, therefore, was never fit for this purpose. Since, however, the levir performed an invalid rite of halitzah, neither he nor his brothers are now permitted to marry the widow. Halitzah by the same levir being the only manner of releasing her, he may be forced, by persuasion or by flagellation, to repeat the rite with the proper shoe. For now the Mitzvah revolved on him alone, and we are permitted to scourge a Jew until he perform the required Mitzvot.
This Responsum is addressed to Rabbi Menahem of Würzburg.
SOURCES: Am I, 93, 94.