היו מתענים בזמן בית ראשון
תָּא שְׁמַע, דְּאָמַר רַבִּי אֶלְעָזָר בְּרַבִּי צָדוֹק: אֲנִי מִבְּנֵי בָנָיו שֶׁל סְנָאָה בֶּן בִּנְיָמִין, וּפַעַם אַחַת חָל תִּשְׁעָה בְּאָב לִהְיוֹת בְּשַׁבָּת, וּדְחִינוּהוּ לְאַחַר הַשַּׁבָּת, וְהִתְעַנִּינוּ בּוֹ וְלֹא הִשְׁלַמְנוּהוּ — מִפְּנֵי שֶׁיּוֹם טוֹב שֶׁלָּנוּ הוּא. הָתָם נָמֵי, לְצַעוֹרֵי נַפְשֵׁיהּ בְּעָלְמָא הוּא.
The Gemara cites another proof: Come and hear, as Rabbi Elazar, son of Rabbi Tzadok, said: I am a descendant of Senaah, son of the tribe of Benjamin, and once the Ninth of Av occurred on Shabbat, and we postponed the fast until after Shabbat, as Shabbat supersedes the fast of the Ninth of Av. And we fasted on that day, but we did not complete the fast, due to the fact that the tenth of Av is a holiday of ours, a private holiday for our family (26a), and one does not fast on holidays. This proves that a fast of only a few hours is nevertheless called a fast. The Gemara rejects this claim: There too, they did so merely to cause themselves distress.