Nedarim9: 4
וְעוֹד אָמַר רַבִּי מֵאִיר: פּוֹתְחִין לוֹ מִן הַכָּתוּב שֶׁבַּתּוֹרָה, וְאוֹמְרִים לוֹ: ,,אִלּוּ הָיִיתָ יוֹדֵעַ שֶׁאַתָּה עוֹבֵר עַל 'לֹא תִקֹּם', וְעַל 'לֹא תִטֹּר', וְעַל 'לֹא תִשְׂנָא אֶת אָחִיךָ בִּלְבָבֶךָ', 'וְאָהַבְתָּ לְרֵעֲךָ כָּמוֹךָ', 'וְחֵי אָחִיךָ עִמָּךְ' — שֶׁמָּא יַעֲנִי וְאֵין אַתָּה יָכוֹל לְפַרְנְסוֹ”. וְאָמַר: ,,אִלּוּ הָיִיתִי יוֹדֵעַ שֶׁהוּא כֵן — לֹא הָיִיתִי נוֹדֵר!” — הֲרֵי זֶה מֻתָּר.
R' Meir also said: They can find ground to annul his neder from what is written in the Torah, and they say to him: “If you had known that you transgress `You shall not take vengeance' (Lev. 19:18), or `You shall not bear a grudge' (ibid.), or `You shall not hate your brother in your heart' (ibid. v. 17), or `You shall love your fellow as yourself' (ibid. v. 18), [or] `That your brother may live with you' (ibid. 25:36) —- perhaps he will grow poor, and you will not be able to support him [would you have vowed?]” If he said: “Had I known that this was so, I would not have made the neder!” —- it is permitted.
Nedarim9: 5
פּוֹתְחִין לָאָדָם בִּכְתֻבַּת אִשְׁתּוֹ. וּמַעֲשֶׂה בְאֶחָד שֶׁנָּדַר מֵאִשְׁתּוֹ הֲנָאָה וְהָיְתָה, כְתֻבָּתָהּ אַרְבַּע מֵאוֹת דִּינָרִין, וּבָא לִפְנֵי רַבִּי עֲקִיבָא, וְחִיְּבוֹ לִתֶּן לָהּ כְּתֻבָּתָהּ. אָמַר לוֹ: ,,רַבִּי! שְׁמֹנֶה מֵאוֹת דִּינָרִין הִנִּיחַ אַבָּא, וְנָטַל אָחִי אַרְבַּע מֵאוֹת וַאֲנִי אַרְבַּע מֵאוֹת, לֹא דַיָּהּ שֶׁתִּטּוֹל הִיא מָאתַיִם, וַאֲנִי מָאתַיִם?” אָמַר לוֹ רַבִּי עֲקִיבָא: ,,אֲפִלּוּ אַתָּה מוֹכֵר שְׂעַר רֹאשְׁךָ, אַתָּה נוֹתֵן לָהּ כְּתֻבָּתָהּ”. אָמַר לוֹ: ,,אִלּוּ הָיִיתִי יוֹדֵעַ שֶׁהוּא כֵן — לֹא הָיִיתִי נוֹדֵר!” וְהִתִּירָהּ רַבִּי עֲקִיבָא.
They can find grounds to annul a man's neder by [reason of] his wife's kesubah. It happened once that a person made a neder prohibiting benefit from his wife, and her kesubah was four hundred dinars. He came before R' Akiva, who obligated him to pay her kesubah to her. He said to him: “Rabbi! Father left eight hundred dinars, my brother took four hundred, and I took four hundred. Is it not enough that she should take two hundred and I, two hundred?” R' Akiva said to him: “Even if you have to sell the hair on your head, you must pay her kesubah to her.” He said to him: “Had I known that this was so, I would not have made the neder.” Thereupon, R' Akiva permitted her.