אֵלּוּ נְדָרִים. בַּגְּמָרָא מְפָרֵשׁ דִּנְדָרִים וּשְׁבוּעוֹת קָתָנֵי, דְּבִלְשׁוֹן חֲכָמִים שְׁבוּעוֹת בִּכְלַל נְדָרִים הֵם: ואלו נדרים – In the Gemara (Tractate Nedarim 80b) it explains that vows and oaths are taught, that in the language of the Sages, oaths are within the category of vows.
אִם אֶרְחָץ וְאִם לֹא אֶרְחָץ. הָכִי קָאָמַר, הֲנָאַת רְחִיצָה אֲסוּרָה עָלַי לְעוֹלָם אִם אֶרְחַץ הַיּוֹם, הֲרֵי נֶדֶר. אִם לֹא אֶרְחַץ, שְׁבוּעָה שֶׁלֹּא אֶרְחַץ, הֲרֵי שְׁבוּעָה. וְכֵן אִם אֶתְקַשֵּׁט, הֲנָאַת קִשּׁוּט אֲסוּרָה עָלַי לְעוֹלָם אִם אֶתְקַשֵּׁט הַיּוֹם, אִם לֹא אֶתְקַשֵּׁט, שְׁבוּעָה שֶׁלֹּא אֶתְקַשֵּׁט: אם ארחץ ואם לא ארחץ – this is what it said: “the benefit of washing is forbidden upon me forever if I shall wash today,” behold this is a vow. “If I shall not wash, an oath that I shall not wash,” behold this is an oath. And similarly, “if I shall adorn myself, the benefit of adorning/dressing is forbidden upon me forever if I adorn myself today,” “if I don’t adorn myself,” is an oath that I will not adorn myself.
אָמַר רַבִּי יוֹסֵי אֵין אֵלּוּ נִדְרֵי עִנּוּי נֶָפֶשׁ. אַנֶּדֶר בִּלְבַד פָּלֵיג רַבִּי יוֹסֵי עַל תַּנָּא קַמָּא, וְאָמַר דַּהֲנָאַת רְחִיצָה אֲסוּרָה עָלַי לְעוֹלָם אִם אֶרְחַץ הַיּוֹם, אֵין זֶה נֶדֶר שֶׁל עִנּוּי נֶפֶשׁ, שֶׁהֲרֵי אֶפְשָׁר לָהּ שֶׁלֹּא תִּרְחַץ הַיּוֹם וְלֹא תִהְיֶה הֲנָאַת רְחִיצָה אֲסוּרָה עָלֶיהָ לְעוֹלָם, וּמְנִיעַת יוֹם אֶחָד מֵרְחִיצָה אֵינוֹ עִנּוּי נֶפֶשׁ, דְּנִוּוּל שֶׁל יוֹם אֶחָד לֹא הָוֵי נִוּוּל. וְאֵין הֲלָכָה כְּרַבִּי יוֹסֵי. וּבֵין הָאָב וּבֵין הַבַּעַל נִדְרֵי עִנּוּי נֶפֶשׁ הוּא דִּמְפֵרִין, דִּכְתִיב (במדבר ל) בֵּין אִישׁ לְאִשְׁתּוֹ בֵּין אָב לְבִתּוֹ, מַקִּישׁ אָב לַבַּעַל, מַה בַּעַל אֵינוֹ מֵפֵר אֶלָּא נִדְרֵי עִנּוּי נֶפֶשׁ, אַף אָב אֵינוֹ מֵפֵר אֶלָּא נִדְרֵי עִנּוּי נֶפֶשׁ. וְרַמְבַּ"ם פָּסַק שֶׁהָאָב מֵפֵר כָּל נְדָרִים וּשְׁבוּעוֹת, אֲפִלּוּ אוֹתָן שֶׁאֵינָן שֶׁל עִנּוּי נֶפֶשׁ, שֶׁנֶּאֱמַר (שם) כָּל נְדָרֶיהָ וֶאֱסָרֶיהָ: אמר ר"י אין אלו נדרי עינוי נפש (vows referring to privation of the necessities of life) – regarding the vow alone Rabbi Yossi disputes the first Tanna/teacher, and [when he] states that the benefit of washing is forbidden upon me if I shall wash today,” this is not a vow of privation of the necessities of life, for behold, it is possible for her that she will not wash today and that the benefit of washing won’t be forbidden upon her forever. But the prevention/refraining from washing for one day is not a privation of the necessities of life, for a neglected appearance for one day (by not bathing) is not considered self-neglect (see Tractate Nedarim 80a). But the Halakha is not according to Rabbi Yossi. But whether the father or the husband, vows of privation of the necessities of life are ones that are absolved, as it is written (Numbers 30:17): “[These are the laws that the LORD enjoined upon Moses] between a man and his wife, and between a father and his daughter [while in her father’s household by reason of her youth],” there is an analogy between two laws that rest on a biblical intimation of the father to the husband. Just as the husband does not absolve anything other than vows of privation of the necessities of life, so also the father does not absolve anything other than vows of privation of the necessities of life. But Maimonides made the legal determination that the father absolves all vows and oaths, even those that are not referring to privation of the necessities of life, as it states (Numbers 30:6): “none of her vows or self-imposed obligations [shall stand].”