Responsa for Eruvin 81:11

מאי לאו אכולהו לא אחנוכה ופורים

stated: 'I am one of the descendants of Seneab of the tribe of Benjamin. Once it happened that the Ninth of Ab fell on a Sabbath and we postponed it to the following Sunday<span class="x" onmousemove="('comment',' Lit., 'to after the Sabbath'.');">³⁰</span> when we fasted but did not complete the fast because that day was our festival.'<span class="x" onmousemove="('comment',' Ta'an. 12a. The tenth of Ab was allotted to them as the day on which they were entitled to bring the offering of wood for the Temple altar. The families that were entitled to such a privilege kept the respective days allotted to them as a family festival. (V. Rashi a.l. and cf. Ta'an. 26a, 28a) .');">³¹</span> The reason [then<span class="x" onmousemove="('comment',' Why they did not complete the postponed fast.');">³²</span>

Teshuvot Maharam