The Shulchan Aruch · Yoreh De'ah
יורה דעה רכ״חYoreh De'ah 228
Siman 228 of 402 in Yoreh De'ah — 51 se'ifim
Se’if 1א׳
מִי שֶׁנָּדַר וְנִתְחָרֵט, יֵשׁ תַּקָּנָה עַל יְדֵי חֲרָטָה, וַאֲפִלּוּ נָדַר בֶּאֱלֹהֵי יִשְׂרָאֵל. כֵּיצַד יַעֲשֶׂה, יֵלֵךְ אֵצֶל חָכָם מֻמְחֶה, דְּגָמִיר וְסָבִיר, וְאִם אֵין יָחִיד מֻמְחֶה יֵלֵךְ אֵצֶל שְׁלֹשָׁה הֶדְיוֹטוֹת, וְהוּא דִּגְמִירֵי לְהוּ וּסְבִירֵי וְגַם יוֹדְעִים לִפְתֹּחַ לוֹ פֶּתַח, וְיַתִּירוּ לוֹ. וְהָאִדָּנָא אֵין מֻמְחֶה שֶׁיְּהֵא רָאוּי לְהַתִּיר בְּיָחִיד.
One who took a neder [sic: vow] and regrets it, can rectify the acceptance of the neder by having remorse. Even if one took a neder with the name of G-D. What should that person do? They should go to a wise [Torah Scholar] who is an expert, who [is well versed in] learns logical inferences and deductive (talmudic) reasoning. If there is no expert, one should go to three average people. These should be people who study with logical inferences and deductive reasoning, and who also know how to find loopholes; and they will release the vow. Nowadays there is no one considered to be an expert who is able to release a vow solely by themselves.
Se’if 2ב׳
אֵין לְאָדָם לְהַתִּיר לְכַתְּחִלָּה בִּמְקוֹם רַבּוֹ, וְלֹא בְּמָקוֹם שֶׁיֵּשׁ גָּדוֹל מִמֶּנּוּ, אֶלָּא אִם כֵּן נָתַן לוֹ רְשׁוּת (רֹא"שׁ וְרַ"ן). הַגָּה: וּמַתִּירִין ב' ג' נְדָרִים בְּיַחַד לוֹמַר לוֹ: מֻתָּר לְ ךָ. וְכֵן מַתִּירִין לְב' אוֹ לְג' אֲנָשִׁים בְּיַחַד, וְיוּכְלוּ לוֹמַר: מֻתָּר לָכֶם (בֵּית יוֹסֵף סוֹף סִימָן זֶה בְּשֵׁם תְּשׁוּבַת הָרַמְבַּ"ן סִי' רע"ד) וְעַיֵּן לְקַמָּן סוֹף סִימָן זֶה סָעִיף מ"ו.
A person cannot nullify [another person's nederim] in an ideal way in-front of his rabbi or in a place in which there's a great person unless they give you permission. Rama: And you can nullify two or three nederim at once and you can nullify two or three people's nederaim at once.
Se’if 3ג׳
כֵּיצַד הִיא הַהַתָּרָה, יֹאמַר לוֹ ג' פְּעָמִים: מֻתָּר לְךָ, אוֹ שָׁרוּי לְךָ, אוֹ מָחוּל לְךָ, בְּכָל לָשׁוֹן שֶׁיֹּאמַר, (בֵּית יוֹסֵף בְּשֵׁם הָרַמְבַּ"ם), וַאֲפִלּוּ מְעֻמָּד, וּבִקְרוֹבִים, וּבַלַּיְלָה, וּבְשַׁבָּת, אֲפִלּוּ אִם הָיָה אֶפְשָׁר לוֹ מֵאֶתְמוֹל לִשָּׁאֵל עָלָיו, וּבִלְבַד שֶׁיִּהְיֶה לְצֹרֶךְ הַשַּׁבָּת, כְּגוֹן שֶׁנָּדַר שֶׁלֹּא לֶאֱכֹל אוֹ לִבָּטֵל מֵעֹנֶג הַשַּׁבָּת. וְחֶרְמֵי צִבּוּר, נָהֲגוּ לְהַתִּיר אַף עַל פִּי שֶׁאֵינָם לְצֹרֶךְ הַשַּׁבָּת.
How can you nullify a never? You say three times "mutar lach" or "mochal lach" (you can say this in any language). Even if the people are standing, are relatives, it's night time, and it's Shabbos, even if the vow was taken yesterday (before Shabbos), as long as it is necessary for Shabbos, for example a vow not to eat, to avoid participating in oneg shabbos. And (if one vows) to distance oneself from the congregation, we say you can nullify the vow even it isn't necessary for Shabbos.
Shulchan Aruch, Yoreh De'ah — Torat Emet 357 edition, via Sefaria — public domain
English: Sefaria Community Translation — CC0
English rendered from the Hebrew for this app — The Gematria's own rendering program. A rendering of the words, not a ruling; practical halacha is learned with a rav