Responsa for Yevamot 209:17
אלא מנין שאפי' נחתם מתקרע שנאמר (דברים ד, ז) מי כה' אלהינו בכל קראנו אליו והכתיב (ישעיהו נה, ו) דרשו ה' בהמצאו לא קשיא הא ביחיד הא בציבור יחיד
R. Samuel b. Unia stated in the name of Rab: Whence is it deduced that a [divine] dispensation against a congregation is not sealed? — [You say] 'Is not sealed'! Surely it is written, For though thou wash thee with nitre, and take thee much soap, yet thine iniquity is marked before Me!<span class="x" onmousemove="('comment',' Jer. II, 22, emphasis on 'marked' 'sealed'. The Hebrew equivalent of the former is [H] which is similar in sound to that of the letters [H]. ');"><sup>40</sup></span> — But [this is the question]: Whence is it deduced that even if it has been sealed it is torn up? — From the Scriptural text, What … as the Lord our God is whensoever we call upon him.<span class="x" onmousemove="('comment',' Deut. IV, 7. ');"><sup>41</sup></span> But, surely, it is written, Seek ye the Lord while He may be found!<span class="x" onmousemove="('comment',' Isa. LV, 6, emphasis on while he may be found, implying that there are times when he may not be found! ');"><sup>42</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.