Related for Beitzah 2:2
חָל לִהְיוֹת אַחַר הַשַּׁבָּת, בֵּית שַׁמַּאי אוֹמְרִים, מַטְבִּילִין אֶת הַכֹּל מִלִּפְנֵי הַשַּׁבָּת, וּבֵית הִלֵּל אוֹמְרִים, כֵּלִים מִלִּפְנֵי הַשַּׁבָּת, וְאָדָם בַּשַּׁבָּת:
If yom tov fell after Shabbath (i.e., on Sunday), Beth Shammai say: Everything is immersed before Shabbath. [For one must cleanse himself for the festival, and all that requires immersion, both men and vessels, are immersed before Shabbath]. And Beth Hillel say: Vessels (are immersed) before Shabbath, and men (immerse themselves) on Shabbath. [Vessels are immersed before Shabbath, for since they are fit for something after immersion for which they were not fit before immersion, if they were immersed on Shabbath or yom tov, this would be "amending something" and would be forbidden. "Shabbath" is stated here (rather than "yom tov") to apprise us of the "power" of Beth Hillel, that they permitted one to immerse even on Shabbath; for the impression is given that he does so for the sake of bathing and cooling off, and not (necessarily) for the sake of ritual cleansing.]