The Shulchan Aruch · Yoreh De'ah
יורה דעה רט״וYoreh De'ah 215
Siman 215 of 402 in Yoreh De'ah — 6 se'ifim
Se’if 1א׳
נְדָרִים חָלִים עַל דְּבַר מִצְוָה. כֵּיצַד, אָמַר: קוּנָם סֻכָּה שֶׁאֲנִי יוֹשֵׁב, לוּלָב אֲנִי נוֹטֵל, אָסוּר לִישֵׁב בַּסֻכָּה וְלִטֹּל לוּלָב. הַגָּה: וְיֵשׁ אוֹמְרִים שֶׁמַּלְקִין אוֹתוֹ עַל שֶׁנָּדַר לְבַטֵּל הַמִּצְוָה, וּמַתִּירִין לוֹ נִדְרוֹ וּמְקַיֵּם הַמִּצְוָה (מָרְדְּכַי רֵישׁ שְׁבוּעוֹת שְׁתַּיִם בְּשֵׁם ר"ח) ; וְיֵשׁ אוֹמְרִים דְּאֵין מַלְקוֹת בְּנֶדֶר שָׁוְא, רַק גַּבֵּי שְׁבוּעַת שָׁוְא (מָרְדְּכַי מָצָא בְּשֵׁם ראבי"ה ור"ן וְרֹא"שׁ בִּנְדָרִים וְעַיֵּן בֵּית יוֹסֵף סִימָן רל"ו), וְכֵן עִקָּר.
Vows take effect upon a thing of a mitzvah. How so? He said: konam (forbidden as an offering is) is the sukkah (the booth of the festival) that I sit in, the lulav (the palm branch taken and waved on the festival of Sukkot) that I take — he is forbidden to sit in the sukkah and to take the lulav. Hagah [Rema]: And there are those who say that they flog him for having vowed to annul the mitzvah, and they release his vow for him and he performs the mitzvah (Mordechai, the beginning of the chapter "Oaths, two", in the name of Rabbeinu Chananel); and there are those who say that there is no flogging in a vain vow, but only in a vain oath (Mordechai found, in the name of Raavyah and the Ran and the Rosh in Nedarim, and see Beit Yosef, siman 236), and so is the main ruling.
Se’if 2ב׳
נָדַר לְהִתְעַנּוֹת זְמַן יָדוּעַ וְאֵרַע בּוֹ שַׁבָּתוֹת וְיָמִים טוֹבִים וְרֹאשׁ חֹדֶשׁ, מַתִּירִין לוֹ נִדְרוֹ וּפוֹתְחִין לוֹ בָּהֶם שֶׁאוֹמְרִים לוֹ: אִלּוּ שַׂמְתָּ עַל לִבְּךָ שֶׁיִּפְגְּעוּ בְּתוֹךְ הַזְּמַן הַזֶּה אֵלּוּ הַיָּמִים לֹא הָיִיתָ נוֹדֵר, וְהֻתַּר כָּל הַנֶּדֶר.
He vowed to fast a known period, and Sabbaths and festival days and the New Moon fell within it — they release his vow for him, and they open for him with them, in that they say to him: had you set upon your heart that these days would meet you within this period, you would not have vowed. And the whole vow is released.
Se’if 3ג׳
בַּמֶּה דְּבָרִים אֲמוּרִים שֶׁצָּרִיךְ הַתָּרָה, כְּשֶׁקִּבְּלוֹ בִּלְשׁוֹן נֶדֶר, שֶׁאָמַר: קוּנָם אֲכִילַת יָמִים כָּךְ וְכָךְ עָלַי; אֲבָל אִם לֹא הוֹצִיאוֹ אֶלָּא בִּלְשׁוֹן קַבָּלַת תַּעֲנִית, אֵינוֹ דּוֹחֶה לֹא שַׁבָּת וְיוֹם טוֹב וְרֹאשׁ חֹדֶשׁ וְלֹא חֲנֻכָּה וּפוּרִים וְאֵינוֹ צָרִיךְ הַתָּרָה, וַאֲפִלּוּ לֹא קִבֵּל עָלָיו לְהִתְעַנּוֹת אֶלָּא בְּשַׁבָּת וְיוֹם טוֹב בִּלְבַד וְעַיֵּן בא"ח סִימָן תי"ח.
In what case are these words said, that he requires release? Where he accepted it in the language of a vow, saying: konam is the eating of such-and-such days upon me. But if he uttered it only in the language of the acceptance of a fast, it does not override the Sabbath or a festival day or the New Moon, nor Chanukah and Purim, and it requires no release — and even if he accepted upon himself to fast only on the Sabbath and on a festival day. And see in Orach Chayim, siman 418.
Shulchan Aruch, Yoreh De'ah — Torat Emet 357 edition, via Sefaria — public domain
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