Halacha

הלכה א
מִי שֶׁנִּשְׁבַּע שְׁבוּעַת בִּטּוּי וְנִחַם עַל שְׁבוּעָתוֹ וְרָאָה שֶׁהוּא מִצְטַעֵר אִם יְקַיֵּם שְׁבוּעָה זוֹ וְנֶהְפְּכָה דַּעְתּוֹ לְדַעַת אַחֶרֶת. אוֹ שֶׁנּוֹלַד לוֹ דָּבָר שֶׁלֹּא הָיָה בְּדַעְתּוֹ בִּשְׁעַת הַשְּׁבוּעָה וְנִחַם בִּגְלָלוֹ. הֲרֵי זֶה נִשְׁאַל לְחָכָם אֶחָד אוֹ לִשְׁלֹשָׁה הֶדְיוֹטוֹת בְּמָקוֹם שֶׁאֵין שָׁם חָכָם וּמַתִּירִין לוֹ שְׁבוּעָתוֹ. וְיִהְיֶה מֻתָּר לַעֲשׂוֹת דָּבָר שֶׁנִּשְׁבַּע שֶׁלֹּא לַעֲשׂוֹתוֹ. אוֹ שֶׁלֹּא לַעֲשׂוֹת דָּבָר שֶׁנִּשְׁבַּע לַעֲשׂוֹתוֹ. וְזֶהוּ הַנִּקְרָא הֶתֵּר שְׁבוּעוֹת:
כסף משנה
1.
[The following rules apply when] a person took a sh'vuat bitui1Kiryat Sefer emphasizes that the concept of repealing an oath applies only with regard to a sh'vuat bitui that involves the future. With regard to a sh'vuat bitui that involves the past, an oath taken in vain, a sh'vuat hapikadon, or an oath regarding testimony, it does not apply. These oaths cannot be repealed for the transgression was performed at the time they were uttered.
More particularly, as the Radbaz explains, there is a difference between a sh'vuat bitui that involves the future and one that involves the past. For when taking a sh'vuat bitui that involves the past as well, as soon as one utters the oath it is false. Nevertheless, he states that it is customary to repeal even this oath to minimize one's punishment.
and [then] regretted having taken the oath. If he sees that he will suffer if he upholds this oath and his intent changes or a factor occurred that was not in his intent originally when he took the oath and he changed his mind because of this, he may appeal2The Rambam uses the passive form, nishal, rather than the active form sho'el. Tosafot Yom Tov, Shabbat 24:5 explains that form is used because the person asked for the repeal of the oath is asked many questions by the sage. [to be released from his oath] from one sage3The sage must be of unique distinction in Torah knowledge to be given the privilege of releasing oaths alone. Nevertheless, he need not have been granted the special semichah extending back to Moses our teacher. For the Torah does not describe the judges with the term elohim in the passage concerning oaths (Rabbenu Nissim). - or from three ordinary people4In his Kessef Mishneh, Rav Yosef Caro maintains that the Rambam's words can be interpreted simply: Even three ordinary people can perform this function. The Radbaz, by contrast, maintains that the intent is three Torah scholars who are knowledgeable, but are not worthy of being called sages. In his Shulchan Aruch (Yoreh De'ah 228:1), Rav Caro, however, rules that the three men repealing the oath must be knowledgeable. He also states that in the present age, there are no sages of the stature to repeal an oath alone. in a place where there are no sages. His oath is repealed and he is permitted to perform the matter that he took the oath not to do or not to do the matter that he took an oath to do. This is called the release of an oath.

הלכה ב
וְדָבָר זֶה אֵין לוֹ עִקָּר כְּלָל בַּתּוֹרָה שֶׁבִּכְתָב. אֶלָּא כָּךְ לָמְדוּ מִמּשֶׁה רַבֵּנוּ מִפִּי הַקַּבָּלָה שֶׁזֶּה הַכָּתוּב (במדבר ל ג) "לֹא יַחֵל דְּבָרוֹ" שֶׁלֹּא יְחַלֵּל הוּא בְּעַצְמוֹ דֶּרֶךְ קַלּוּת רֹאשׁ בִּשְׁאָט נֶפֶשׁ כָּעִנְיָן שֶׁנֶּאֱמַר (ויקרא יט יב) "וְחִלַּלְתָּ אֶת שֵׁם אֱלֹהֶיךָ". אֲבָל אִם נִחַם וְחָזַר בּוֹ חָכָם מַתִּיר לוֹ:
כסף משנה
2.
This provision has no source in the Written Law.5See Chagigah 10a which states: "The release of vows is hanging in the air and they have nothing to depend on." Instead, we learned from Moses our teacher through the Oral Tradition that the phrase [Numbers 30:3]: "He should not desecrate his word" means that he himself should not abuse it in a frivolous and brazen manner, as [Leviticus 19:13] states: "[For] you will desecrate the name of Your God."6That verse begins: "You shall not take a false oath in My name." Nevertheless, if a person changed his mind and retracted, a sage may release him [from the oath].7See also Chapter 12, Halachah 12.

הלכה ג
וְאֵין אָדָם יָכוֹל לְהַתִּיר שְׁבוּעַת עַצְמוֹ. וְאֵין אָדָם רַשַּׁאי לְהַתִּיר שְׁבוּעָה אוֹ נֵדֶר בְּמָקוֹם שֶׁיֵּשׁ גָּדוֹל מִמֶּנּוּ בְּחָכְמָה. וּבְמָקוֹם שֶׁיֵּשׁ בּוֹ רַבּוֹ אָסוּר לוֹ לְהַתִּיר אֶלָּא מִדַּעַת רַבּוֹ:
כסף משנה
3.
It is not possible for a person to release himself from his own oath. A person does not have the license to release an oath or a vow in a place where there is a person whose knowledge surpasses his own.8This is an expression of respect for the greater scholar. The Radbaz states that he has not seen this restriction observed and question why this leniency is taken. If the greater scholar grants permission, the lesser scholar may release the oath [Shulchan Aruch (Yoreh De'ah 228:2)]. Nevertheless, after the fact, if a lesser scholar releases an oath even without permission, the release is binding. In a place where his teacher is found, he may only release a vow with the consent of his teacher.

הלכה ד
זֶה שֶׁנִּשְׁבַּע הוּא שֶׁיָּבוֹא לִפְנֵי הֶחָכָם לְהַתִּיר לוֹ בֵּין אִישׁ בֵּין אִשָּׁה. וְאֵינוֹ עוֹשֶׂה שָׁלִיחַ לְהִשָּׁאֵל לוֹ עַל נִדְרוֹ. וְהַבַּעַל נַעֲשֶׂה שָׁלִיחַ לַחֲרָטַת אִשְׁתּוֹ וּמַתִּירִין לָהּ וּבִלְבַד שֶׁיִּהְיוּ הַשְּׁלֹשָׁה מְקֻבָּצִים אֲבָל לֹא יְקַבֵּץ אוֹתָן לְהַתִּיר לָהּ לְכַתְּחִלָּה. וְאֵינוֹ נַעֲשֶׂה שָׁלִיחַ לְהַתִּיר נֵדֶר לְאִשְׁתּוֹ:
כסף משנה
4.
The person who took the oath - whether male or female - must himself come before the sage to be released. He may not appoint an agent to seek that he be released from his vow.9Nor may he send a written request to the court (Radbaz). He may, however, use a translator [Jerusalem Talmud (Nedarim 10:8); Rama (Yoreh De'ah 228:16)]. A husband may, however, become an agent to express his wife's regret and we release [the oath] for her.10For a husband and his wife are considered as the same person. [This applies] provided the three judges had already gathered together. He should not, however, gather them together at the outset to release her [oath].11Nedarim 8b explains that if a person takes the effort to gather a court together, we fear that he will also exaggerate his wife's statements and the court's cross-examination of him will not be effective. Nor may he serve as an agent to have his wife's vow released.12I.e., he may not serve as one of the three judges who release the vow [Radbaz; Shulchan Aruch (Yoreh De'ah 234:57)]. This interpretation resolves the objection raised by the Ra'avad. Since he is identified with his wife to the extent that he is considered as the same person, he cannot act objectively with regard to her issues.

הלכה ה
כֵּיצַד מַתִּירִין. יָבוֹא הַנִּשְׁבָּע לְחָכָם הַמֻּבְהָק אוֹ לִשְׁלֹשָׁה הֶדְיוֹטוֹת אִם אֵין שָׁם מֻמְחֶה. וְאוֹמֵר אֲנִי נִשְׁבַּעְתִּי עַל כָּךְ וְכָךְ וְנִחַמְתִּי. וְאִלּוּ הָיִיתִי יוֹדֵעַ שֶׁאֲנִי מִצְטַעֵר בְּדָבָר זֶה עַד כֹּה אוֹ שֶׁאֵרַע לִי כָּךְ וְכָךְ לֹא הָיִיתִי נִשְׁבַּע וְאִלּוּ הָיְתָה דַּעְתִּי בְּעֵת הַשְּׁבוּעָה כְּמוֹ עַתָּה לֹא הָיִיתִי נִשְׁבַּע. וְהֶחָכָם אוֹ גְּדוֹל הַשְּׁלֹשָׁה אוֹמֵר לוֹ וּכְבָר נִחַמְתָּ. וְהוּא אוֹמֵר לוֹ הֵן. חוֹזֵר וְאוֹמֵר לוֹ שָׁרוּי לְךָ אוֹ מֻתָּר לְךָ אוֹ מָחוּל לְךָ וְכָל כַּיּוֹצֵא בְּעִנְיָן זֶה בְּכָל לָשׁוֹן. אֲבָל אִם אָמַר לוֹ מוּפָר לְךָ אוֹ נֶעֶקְרָה שְׁבוּעָתְךָ וְכָל כַּיּוֹצֵא בְּעִנְיָן זֶה לֹא אָמַר כְּלוּם. שֶׁאֵין מֵפֵר אֶלָּא הַבַּעַל אוֹ הָאָב אֲבָל הֶחָכָם אֵינוֹ אוֹמֵר אֶלָּא לְשׁוֹן הַתָּרָה וּמְחִילָה:
כסף משנה
5.
How do we release [an oath]? The person who took the oath must come before the distinguished sage or three ordinary people if there is no expert.13See Halachah 1. He says: "I took an oath concerning this and this and I have changed my mind. If I knew that I would feel such discomfort concerning this, I would not have taken the oath. If, at the time of the oath, my understanding was as it is now, I would not have taken the oath."
The wise man or the foremost among the three asks: "Have you already changed your mind?"
He answers: "Yes."
He then tells him: "It is permitted for you," "It is released for you," "It is absolved for you," or the like with this intent in any language.14I.e., he need not make a formal statement in Hebrew.
In his Commentary to the Mishnah, Nedarim 10:8, the Rambam elaborates on this rite:

He tells [the sage or the three ordinary people]: "I took a vow... and I changed my mind."
They ask him the reason he changed his mind and he tells them.... The foremost among the three asks: "At the time, you took the vow, had you known that this and this would occur to you, would you have taken the vow?" And he says: "No."...
He asks him: "Do you regret this oath?" and he says: "Yes."
The foremost of the three addresses him with this wording: "It is permitted for you; it is permitted for you; it is permitted for you. It is absolved for you in the heavenly academy and the earthly academy as it is written (Numbers 15:26 : 'And it will be forgiven for the entire congregation of Israel and the stranger who dwells among them for the entire nation has acted inadvertently.'

If, however, he says: "[The oath] is nullified for you," "Your oath is uprooted," or anything with that intent, his statements are of no consequence, because only a husband or a father can nullify an oath.15The Torah gave them this power. See Hilchot Nedarim, Chapter 13, for an explanation of this issue. A sage, by contrast, may use only an expression conveying release or absolution.16The Radbaz explains that the term "nullify" or "uproot" imply being overpowered by a stronger authority without reason. For the woman is placed under the control of her husband or father and with or without reason, he may nullify her oath even against her will. His authority overpowers the oath, as it were. "Permit," "release," or the like, by contrast, imply that a decision is made on the basis of logic and the oath is revoked as if it never existed. See also the Rambam's Commentary to the Mishnah, loc. cit., where he discusses the differences between these two terms.

הלכה ו
הַקְּרוֹבִים כְּשֵׁרִים לְהַתִּיר נְדָרִים וּשְׁבוּעוֹת. וּמַתִּירִין בַּלַּיְלָה וּמְעֻמָּד. שֶׁאֵין הַהֶתֵּר הַזֶּה דִּין. לְפִיכָךְ נִשְׁאָלִין לִשְׁבוּעוֹת וְלִנְדָרִים בְּשַׁבָּת אִם הָיוּ לְצֹרֶךְ הַשַּׁבָּת. כְּגוֹן שֶׁיַּתִּירוּ לוֹ שְׁבוּעָתוֹ כְּדֵי שֶׁיֹּאכַל וְיִשְׁתֶּה הַיּוֹם. וַאֲפִלּוּ הָיָה לוֹ פְּנַאי לְהַתִּיר שְׁבוּעָתוֹ אוֹ נִדְרוֹ מֵעֶרֶב שַׁבָּת הֲרֵי זֶה מַתִּיר בְּשַׁבָּת הוֹאִיל וְהוּא לְצֹרֶךְ הַשַּׁבָּת:
כסף משנה
6.
Relatives are acceptable to release vows17Thus two relatives may sit on the same "court" that releases vows on the day preceding Rosh HaShanah. and oaths.18Although they are not acceptable to serve on the same court with regard to cases of law. [Oaths and vows] can be released at night19In contrast to judgments of law which may be rendered only during the day. and while standing,20In contrast to judgments that are rendered while sitting. for this release is not a judgment.
For this reason, one may request a release of an oath or a vow on the Sabbath21When it is forbidden to render judgments (Hilchot Shabbat 23:14). if it is necessary for the Sabbath,22If, however, it is not for the sake of the Sabbath, it may not be released on the Sabbath, because it is forbidden to perform any activity for the weekdays on the Sabbath (Radbaz). See Hilchot Nedarim 13:8 with regard to the nullification of vows and oaths by a husband or a father. for example, to release his oath so that he can eat and drink today. Even if the person had the opportunity to have his oath or vow released before the Sabbath [and did not], he may have it released on the Sabbath, because it is necessary for the Sabbath.

הלכה ז
רְאוּבֵן שֶׁהִשְׁבִּיעַ לְשִׁמְעוֹן וְעָנָה אָמֵן. אוֹ קִבֵּל הַשְּׁבוּעָה וְנִחַם שִׁמְעוֹן עַל שְׁבוּעָתוֹ וְנִשְׁאַל עָלֶיהָ. אֵין מַתִּירִין לוֹ אֶלָּא בִּפְנֵי רְאוּבֵן שֶׁהִשְׁבִּיעוֹ. וְכֵן אִם נִשְׁבַּע רְאוּבֵן אוֹ נָדַר שֶׁלֹּא יֵהָנֶה מִשִּׁמְעוֹן אוֹ שֶׁלֹּא יֵהָנֶה בּוֹ שִׁמְעוֹן וְנִחַם וְנִשְׁאַל לְחָכָם אֵין מַתִּירִין לוֹ אֶלָּא בִּפְנֵי שִׁמְעוֹן שֶׁנָּדַר מִמֶּנּוּ הֲנָיָה. וַאֲפִלּוּ הָיָה שִׁמְעוֹן קָטָן אוֹ עַכּוּ''ם אֵין מַתִּירִין לוֹ אֶלָּא בְּפָנָיו כְּדֵי שֶׁיֵּדַע הַנִּדָּר שֶׁהִתִּיר זֶה נִדְרוֹ אוֹ שְׁבוּעָתוֹ וּלְפִיכָךְ יֵהָנֶה מִמֶּנּוּ אוֹ יַהֲנֶה לוֹ:
כסף משנה
7.
When Reuven administered an oath to Shimon and [Shimon] answered Amen23Which causes the oath to take effect, as stated in Chapter 2, Halachah 1. or accepted the oath, if Shimon [later] regrets the oath and asks for it to be released, it should not be released except in the presence of Reuven24The Shulchan Aruch (Yoreh De'ah 228:20) states that Reuven must "be notified." The Rama maintains that he must also consent to the oath being released. The Shulchan Aruch also states that this law applies only when the oath was taken in response to a favor the person performed for him. who administered it to him.25Lest Shimon see Reuven not paying attention to the oath and think that he violated the Torah's prohibition. Alternatively, so that Reuven will be embarrassed and not treat oath and vows frivolously [Jerusalem Talmud (Nedarim 5:4)].
The Radbaz and the Hagahot Maimoniot state that, after the fact, if Reuven had the oath released outside Shimon's presence, the release is binding. The Radbaz, however, states that if the oath involves financial claims, the person in whose presence the oath was taken must be present.

Similarly, if Reuven took an oath or a vow not to benefit from Shimon or that Shimon may not benefit from him and changed his mind and appealed to a sage [for the oath or vow to be released], we do not release him from it except in the presence of Shimon from whom he had vowed not to benefit. Even if Shimon was a minor or a gentile,26Who are not obligated in the observance of mitzvot. Nedarim 65a states that since Moses took an oath in the presence of Jethro, his father-in-law, to stay in Midian, he had to have the oath nullified in Jethro's presence. At that time, Jethro was not Jewish. [the oath or vow] is released only in his presence so that the person concerning whom the vow was taken will know that the person had his vow or oath released and thus he will benefit from him.27The standard printed text of the Mishneh Torah concludes "or provide benefit for him." This appears to be a printing error; it is not found in manuscripts or early printings.

הלכה ח
אֶחָד הַנִּשְׁבָּע בֵּינוֹ לְבֵין עַצְמוֹ וְאֶחָד הַנִּשְׁבָּע בָּרַבִּים. וַאֲפִלּוּ נִשְׁבַּע בַּשֵּׁם הַמְיֻחָד בַּה' אֱלֹהֵי יִשְׂרָאֵל וְנִחַם הֲרֵי זֶה נִשְׁאָל עַל שְׁבוּעָתוֹ וּמַתִּירִין לוֹ. נִשְׁבַּע עַל דַּעַת רַבִּים אוֹ שֶׁנָּדַר עַל דַּעַת רַבִּים אֵין מַתִּירִין לוֹ לְעוֹלָם אֶלָּא לִדְבַר מִצְוָה:
כסף משנה
8.
Both a person who took an oath in private and one who took one in public - even one who took an oath in God's ineffable name, [swearing] by God, the Lord of Israel - may appeal for a release of his oath if he changes his mind.28I.e., we do not say that since the respect due God's name will be compromised, the oath may not be released.
If, however, one took an oath or a vow based on the understanding of many others,29At least three (Radbaz, based on Gittin 46a). it may not be released30The Tur and the Shulchan Aruch (Yoreh De'ah228:21) state that we may release the oath or vow if those people consent. The Rama states that the oath can never be released. The difference between these rulings depends on the rationale for this decision. Rabbenu Nissim explains that taking an oath based on the understanding of others reinforces the severity of the oath and prevents it from being repealed. Others explain that the person is merely substituting the others for himself. Just as ordinarily an oath is dependent on his own understanding, now it is dependent on that of others. except for a purpose associated with a mitzvah.31For we assume the others would agree not to enforce the oath when doing so would prevent the fulfillment of a mitzvah (Tosafot, Gittin 36a).

הלכה ט
כֵּיצַד. נִשְׁבַּע וְתָלָה שְׁבוּעָתוֹ בְּדַעַת רַבִּים שֶׁלֹּא יֵהָנֶה בִּפְלוֹנִי לְעוֹלָם וְהֻצְרְכוּ בְּנֵי אוֹתָהּ הָעִיר לִלְמֹד תּוֹרָה אוֹ לְמִי שֶׁיָּמוּל אֶת בְּנֵיהֶם אוֹ שֶׁיִּזְבַּח לָהֶם וְלֹא נִמְצָא אֶלָּא זֶה בִּלְבַד הֲרֵי זֶה נִשְׁאַל לְחָכָם אוֹ לִשְׁלֹשָׁה הֶדְיוֹטוֹת וּמַתִּירִין לוֹ שְׁבוּעָתוֹ וְעוֹשֶׂה לָהֶם מִצְוֹת אֵלּוּ וְנוֹטֵל שְׂכָרוֹ מֵאוֹתָן הָאֲנָשִׁים שֶׁנִּשְׁבַּע שֶׁלֹּא יֵהָנֶה מֵהֶם:
כסף משנה
9.
What is implied? One took an oath and made his oath dependent on the understanding of others that he would not benefit from so-and-so at all and the people of that city needed someone to teach them the Torah, to circumcise their sons, or to perform ritual slaughter on their behalf and they only found this person,32I.e., the person who took the oath. he may ask a sage or three ordinary persons [to release him from his oath]. We release his oath. He may perform these mitzvot on their behalf and he may receive his wage33The Ra'avad objects to the Rambam's ruling, stating that he misinterpreted the passage from Gittin, loc. cit. The Ra'avad continues, explaining that in the situation described by the Rambam, it is preferable for the person to teach without charging a wage. Moreover, he is not responsible for the Torah education of those children and hence, the motivation to have the oath rescinded is not his.
The Kessef Mishneh supports the Rambam's ruling, noting (see Hilchot Talmud Torah 1:2) that a sage is obligated to teach all the students, not only the members of his family. The Radbaz explains that it is preferable that he work for a wage than do so gratuitously, for a person who does not receive a wage for his work will not apply himself sufficiently.
from the people concerning whom he had taken an oath that he would not benefit from them.

הלכה י
מִי שֶׁנִּשְׁבַּע וְלֹא נִחַם עַל שְׁבוּעָתוֹ וּבָא לְבֵית דִּין לְקַיֵּם שְׁבוּעָתוֹ. אִם רָאוּ הַדַּיָּנִין שֶׁהֶתֵּר שְׁבוּעָה זוֹ גּוֹרֵם לְמִצְוָה וּלְשָׁלוֹם בֵּין אִישׁ לְאִשְׁתּוֹ בֵּין אָדָם לַחֲבֵרוֹ וְשֶׁקִּיּוּם שְׁבוּעָה זוֹ גּוֹרֵם לַעֲבֵרָה וְלִקְטָטָה פּוֹתְחִין לוֹ פֶּתַח וְנוֹשְׂאִין וְנוֹתְנִין עִמּוֹ בַּדָּבָר וּמוֹדִיעִין לוֹ דְּבָרִים שֶׁגּוֹרֶמֶת שְׁבוּעָתוֹ עַד שֶׁיִּתְנַחֵם. אִם נִחַם בְּדִבְרֵיהֶם מַתִּירִין לוֹ וְאִם לֹא נִחַם וְעָמַד בְּמִרְיוֹ הֲרֵי זֶה יְקַיֵּם שְׁבוּעָתוֹ:
כסף משנה
10.
[The following laws apply when] a person took an oath, did not regret it, and came to the court to carry out his oath. If the judges saw that releasing this oath will lead to a mitzvah and to peace between a husband and his wife or between a man and his associates and carrying it out will lead to transgression and strife, they encourage him [to take] the option [of having the oath released].34I.e., they try to influence him to change his mind and express his regret. They discuss the matter with him, pointing out the consequences of his oath until he regrets [having taken it].35The Ma'aseh Rokeach explains that we are talking about a situation in which the person feels uncomfortable with keeping the oath in the future, but does not regret having made it. In such a situation, the oath cannot be repealed (see Shulchan Aruch (Yoreh De'ah 228:7). Therefore the court, as the Rambam illustrates, explains the negative consequences of the oath so that the person will feel genuine regret. If he changes his mind because of their words, we release his oath. If he does not change his mind and persists in his stubbornness, he must carry out his oath.

הלכה יא
כֵּיצַד. נִשְׁבַּע שֶׁיְּגָרֵשׁ אֶת אִשְׁתּוֹ אוֹ שֶׁלֹּא יֵהָנֶה יִשְׂרָאֵל מִנְּכָסָיו אוֹ שֶׁלֹּא יֹאכַל בָּשָׂר וְשֶׁלֹּא יִשְׁתֶּה יַיִן שְׁלֹשִׁים יוֹם וְכַיּוֹצֵא בָּזֶה אוֹמְרִים לוֹ בְּנִי אִם תְּגָרֵשׁ אֶת אִשְׁתְּךָ אַתָּה מוֹצִיא לַעַז עַל בָּנֶיךָ וְאוֹמְרִים הָעָם מִפְּנֵי מָה נִתְגָּרְשָׁה אִמָּן שֶׁל אֵלּוּ וּלְמָחָר קוֹרְאִים לָהֶם בְּנֵי גְּרוּשָׁה וְשֶׁמָּא תִּנָּשֵׂא לְאַחֵר וְאִי אַתָּה יָכוֹל לְהַחְזִירָהּ וְכַיּוֹצֵא בִּדְבָרִים אֵלּוּ. וְכֵן זֶה שֶׁנִּשְׁבַּעְתָּ שֶׁלֹּא יֵהָנֶה יִשְׂרָאֵל מִנְּכָסֶיךָ לְמָחָר יִצְטָרֵךְ זֶה וְתִהְיֶה עוֹבֵר עַל (ויקרא כה לו) "וְחֵי אָחִיךָ עִמָּךְ" (ויקרא כה לה) "וְהֶחֱזַקְתָּ בּוֹ" אוֹ (דברים טו ח) (דברים טו יא) "פָּתֹחַ תִּפְתַּח" וְכַיּוֹצֵא בָּהֶן. וְזֶה שֶׁנִּשְׁבַּעְתָּ שֶׁלֹּא תֹּאכַל בָּשָׂר וְשֶׁלֹּא תִּשְׁתֶּה יַיִן שְׁלֹשִׁים יוֹם הֲרֵי אַתָּה פּוֹגֵעַ בָּרֶגֶל וּמְבַטֵּל שִׂמְחַת יוֹם טוֹב וְעֹנֶג שַׁבָּת. אִם אָמַר אִלּוּ הָיִיתִי יוֹדֵעַ זֶה לֹא הָיִיתִי נִשְׁבַּע מַתִּירִין לוֹ וְאִם אָמַר אַף עַל פִּי כֵן לֹא נִחַמְתִּי וְרוֹצֶה אֲנִי בְּכָל זֶה אֵין מַתִּירִין לוֹ:
כסף משנה
11.
What is implied? A person took an oath that he would divorce his wife, that Jews would not benefit from his property, that he would not eat meat or drink wine for thirty days or the like, they tell him: "My son, if you divorce your wife, you will cause malicious gossip to circulate concerning her children36I.e., people will spread rumors that the children were conceived out of adultery and are illegitimate. [for people] will say: 'Why was their mother divorced?' In the future, they will be called: 'the children of the divorcee.' [Moreover,] perhaps she will marry someone else and you will never be able to remarry her"37As stated in Hilchot Gerushin 11:12. and the like.38For example, Nedarim 66b states that we warn him that paying the woman's ketubah is a significant expense.
[And they say:] "The oath you took that Jews should not benefit from your property [is not to your advantage]. Tomorrow, someone may be in need and [by maintaining your oath,] you will violate [the commandments]:39See Hilchot Matanot Aniyim 7:1 which mentions these obligations. "And your brother will live with you and you shall support him" [Leviticus 25:35-36] and "You shall surely open [your hand to him" [Deuteronomy 15:8].
[And they say:] "The oath you took not to eat meat or drink wine for thirty days [is not to your advantage]. [Within that time,] you will encounter a festival and nullify the happiness of the festivals and the pleasure of the Sabbath."40See Hilchot Shabbat 30:10; Hilchot Sh'vitat Yom Tov 6:16,18 which detail how partaking of these foods leads to the fulfillment of these mitzvot.
If he says: "Were I to have known this, I would not have taken the oath," we release him [from the oath]. If he says: "Nevertheless, I have not changed my mind and I desire all of this," we do not release him [from the oath].

הלכה יב
אֵין פּוֹתְחִין בְּנוֹלָד. כֵּיצַד. נִשְׁבַּע שֶׁלֹּא יֵהָנֶה בִּפְלוֹנִי וְנַעֲשָׂה סוֹפֵר הָעִיר. הוֹאִיל וְלֹא נִחַם עַל שְׁבוּעָתוֹ אֵין פּוֹתְחִין לוֹ בְּדָבָר זֶה. וַאֲפִלּוּ אָמַר הוּא מֵעַצְמוֹ אִלּוּ הָיִיתִי יוֹדֵעַ לֹא הָיִיתִי נִשְׁבַּע אֵין מַתִּירִין לוֹ הוֹאִיל וַעֲדַיִן לֹא נִחַם אֶלָּא רְצוֹנוֹ שֶׁלֹּא יֵהָנֶה לוֹ וְשֶׁלֹּא יֵעָשֶׂה זֶה סוֹפֵר. אֲבָל אִם נִחַם הוּא מֵעַצְמוֹ מִפְּנֵי הַנּוֹלָד וְנֶהֶפְכָה דַּעְתּוֹ מַתִּירִין לוֹ. וְכֵן כָּל כַּיּוֹצֵא בָּזֶה:
כסף משנה
12.
We do not encourage one [to take] the option [of having the oath released] because of something that had not occurred [at the time the oath was taken].41The Ra'avad objects to the Rambam's ruling, explaining that we do encourage the person to ask for the repeal of an oath if the factor that caused the oath was a reasonable probability. To support his argument, he refers to Nedarim 64b which states that God encouraged Moses to nullify his vow not to return to Egypt, telling him that the people who caused him to flee had died. The Talmud explains that the individuals concerned, Datan and Aviram, had not actually died; they merely became impoverished and "a poor person is considered as if he died." Since poverty is a frequent occurrence, it was appropriate for God to encourage Moses to ask to have his oath repealed. The Radbaz explains that the Rambam would also accept this principle, but the Kessef Mishneh differs.
What is implied? One took an oath not to derive benefit from so-and-so and that person became the city scribe. Since the person did not regret taking the oath, we do not encourage him [to take] the option [of having the oath released]. Even if he himself said: "If I knew that [he would be given this position], I would not have taken this oath," we still do not release him from it. For he does not regret [having taken the oath]. Instead, his desire is that he should not derive benefit from him, but that person not to be appointed the scribe. If, however, on his own initiative, he regretted because of what took place and his intent changed,42I.e., he regretted taking the oath not to benefit from him, because he realized that he could become the city scribe. we do release the oath. Similar laws apply in all analogous situations.

הלכה יג
מִי שֶׁנִּשְׁבַּע עַל דָּבָר וְנִשְׁבַּע שֶׁלֹּא יַתִּיר שְׁבוּעָה זוֹ וְנִחַם. הֲרֵי זֶה נִשְׁאַל עַל הַשְּׁבוּעָה הָאַחֲרוֹנָה תְּחִלָּה שֶׁנִּשְׁבַּע שֶׁלֹּא יַתִּיר וְאַחַר כָּךְ יִשְׁאַל עַל הָרִאשׁוֹנָה:
כסף משנה
13.
When a person takes an oath concerning a matter and then takes a [second] oath that he will never ask to have the [first] oath repealed, [if] he changes his mind, he must first ask that the second oath - that he would never ask to have the oath repealed - be repealed.43Otherwise, asking for the repeal of the first oath would violate the second oath (Kessef Mishneh). Afterwards, he may ask that the first [oath] be repealed.

הלכה יד
נִשְׁבַּע שֶׁלֹּא יְדַבֵּר עִם פְּלוֹנִי וְנִשְׁבַּע אַחַר כָּךְ שֶׁאִם יִשְׁאַל עַל שְׁבוּעָה זוֹ וְיַתִּירָהּ יִהְיֶה אָסוּר לִשְׁתּוֹת יַיִן לְעוֹלָם וְנִחַם. הֲרֵי זֶה נִשְׁאָל עַל הַשְּׁבוּעָה הָרִאשׁוֹנָה וּמַתִּירָהּ. וְאַחַר כָּךְ יִשְׁאַל עַל הַשְּׁנִיָּה. שֶׁאֵין מַתִּירִין נֵדֶר אוֹ שְׁבוּעָה שֶׁעֲדַיִן לֹא חָלוּ. לְפִיכָךְ אִם הָיָה עוֹמֵד בְּנִיסָן וְנִשְׁבַּע שֶׁלֹּא יֹאכַל בָּשָׂר שְׁלֹשִׁים יוֹם מֵרֹאשׁ חֹדֶשׁ אִיָּר וְנִחַם אֵינוֹ נִשְׁאָל עַד שֶׁיִּכָּנֵס אִיָּר:
כסף משנה
14.
[The following laws apply if] one took an oath that he would not speak to so-and-so and afterwards, took an oath that if he asks for the repeal of this oath and has it released, he will be forbidden to drink wine forever. If he changes his mind, he must first ask for the repeal of the first oath and have it released. Afterwards, he may ask for the repeal of the second oath. For we may not have a vow or an oath repealed before it takes effect.44And the second oath will not take effect until the first oath is released. The Siftei Cohen 228:30 writes that even after the fact, an oath cannot be nullified until it takes effect.
This refers to the repeal of a vow or an oath by a sage. A father or a husband, by contrast, may nullify a vow before it takes effect. See Hilchot Nedarim 12:12.
Accordingly, if during Nisan, a person took an oath that he will not eat meat for thirty days beginning at Rosh Chodesh Iyar, [should] he change his mind, he may not have the oath repealed until [the month of] Iyar begins.

הלכה טו
נִשְׁבַּע שֶׁלֹּא יֵהָנֶה לִפְלוֹנִי וְשֶׁלֹּא יֵהָנֶה לְחָכָם שֶׁיִּשְׁאַל לוֹ עַל שְׁבוּעָה זוֹ. נִשְׁאַל עַל הָרִאשׁוֹנָה וְאַחַר כָּךְ יִשְׁאַל עַל הַשְּׁנִיָּה:
כסף משנה
15.
If a person takes an oath that he will not benefit from so-and-so and that he will not benefit from the sage who releases him from this oath, first he must ask for the repeal of the first [oath] and then for that of the second.45For as above, the second oath cannot be repealed until it takes effect. See the Radbaz who offers explanations why the Rambam includes this and the following halachah though seemingly they could easily be derived from the previous one.

הלכה טז
נִשְׁבַּע שֶׁלֹּא יֵהָנֶה לִפְלוֹנִי וַהֲרֵי הוּא נָזִיר אִם יִשְׁאַל עַל שְׁבוּעָה זוֹ. יִשְׁאַל עַל שְׁבוּעָתוֹ תְּחִלָּה וְאַחַר כָּךְ עַל נְזִירוּתוֹ. וְכֵן כָּל כַּיּוֹצֵא בָּזֶה:
כסף משנה
16.
If a person takes an oath that he will not benefit from so-and-so and that he will become a nazirite if he asks for the repeal of this oath, first he must ask for the repeal of his oath and then for that of his nazirite vow.46Even though it is a mitzvah, a nazirite vow can be repealed. See Hilchot Nazirut 3:10. Similar laws apply in all analogous situations.

הלכה יז
שְׁבוּעָה שֶׁלֹּא אֹכַל הַיּוֹם שְׁבוּעָה שֶׁלֹּא אֹכַל הַיּוֹם שְׁבוּעָה שֶׁלֹּא אֹכַל הַיּוֹם. אוֹ שֶׁאָמַר עַל כִּכָּר זוֹ שְׁבוּעָה שֶׁלֹּא אֹכָלֶנָּה שְׁבוּעָה שֶׁלֹּא אֹכָלֶנָּה שְׁבוּעָה שֶׁלֹּא אֹכָלֶנָּה. וְנִשְׁאַל עַל שְׁבוּעָה רִאשׁוֹנָה וְהֻתְּרָה הֲרֵי זֶה חַיָּב מִשּׁוּם שְׁבוּעָה שְׁנִיָּה. וְכֵן אִם נִשְׁאַל עַל הַשְּׁנִיָּה חַיָּב מִשּׁוּם שְׁלִישִׁית. נִשְׁאַל עַל הַשְּׁלִישִׁית בִּלְבַד חַיָּב מִשּׁוּם רִאשׁוֹנָה וּשְׁנִיָּה. נִשְׁאַל עַל הַשְּׁנִיָּה חַיָּב מִשּׁוּם רִאשׁוֹנָה [וּשְׁלִישִׁית]. אִם כֵּן מִפְּנֵי מָה אָמְרוּ אֵין שְׁבוּעָה חָלָה עַל שְׁבוּעָה. שֶׁאִם לֹא נִשְׁאַל וַאֲכָלָהּ אֵינוֹ חַיָּב אֶלָּא אַחַת כְּמוֹ שֶׁבֵּאַרְנוּ:
כסף משנה
17.
[The following rules apply when a person says:] "I am taking [an oath that I will not eat today, [I am taking] an oath that I will not eat today, [I am taking] an oath that I will not eat today," or "With regard to this loaf, [I am taking] an oath that I will not eat it, [I am taking] an oath that I will not eat it, [I am taking] an oath that I will not eat it." If he asks for the repeal of the first oath and it is released, he is, nevertheless, liable for the second oath.47For even though he is not liable for that second oath until the first oath is repealed, the second oath is not nullified. Instead, it is valid and thus can take effect after the first oath is nullified. Similarly, if he asks for the repeal of the second oath, he is liable for the third oath. If he asks for the repeal of only the third oath, he is liable for the first and second. [Similarly,] if he asks for the repeal of the second oath,48The Rambam maintains that since this oath is prevented from taking effect only because of another oath, one can ask for it to be repealed. Based on this view, the Radbaz maintains that one may have all the relevant oaths repealed with one request. There are, however, other views (the Ramban), who maintain that since the second and third oaths have not taken effect, they cannot be repealed. The Shulchan Aruch (Yoreh De'ah 228:46) cites the Ramban's view, while the Siftei Cohen 228:110 mentions that of the Rambam. he is liable for the first.
If so, what is the meaning of the statement: "An oath cannot take effect [when the matter it concerns is already forbidden] by an oath"? That if the person did not repeal [any of] the oaths and ate [the forbidden article], he would be liable only once, as we explained.49Chapter 4, Halachah 10.

הלכה יח
מִי שֶׁנִּשְׁבַּע שְׁבוּעַת בִּטּוּי לְהַבָּא וְשִׁקֵּר בִּשְׁבוּעָתוֹ. כְּגוֹן שֶׁנִּשְׁבַּע שֶׁלֹּא יֹאכַל פַּת זוֹ וַאֲכָלָהּ וְאַחַר שֶׁאֲכָלָהּ קֹדֶם שֶׁיָּבִיא קָרְבָּנוֹ אִם הָיָה שׁוֹגֵג אוֹ קֹדֶם שֶׁיִּלְקֶה אִם הָיָה מֵזִיד נִחַם וְנִשְׁאַל לְחָכָם וְהִתִּירָהּ לוֹ. הֲרֵי זֶה פָּטוּר מִן הַקָּרְבָּן אוֹ מִן הַמַּלְקוֹת. וְלֹא עוֹד אֶלָּא אֲפִלּוּ כְּפָתוּהוּ לִלְקוֹת וְנִשְׁאַל וְהִתִּירוּ לוֹ קֹדֶם שֶׁיַּתְחִילוּ לְהַלְקוֹתוֹ הֲרֵי זֶה פָּטוּר:
כסף משנה
18.
When a person takes a sh'vuat bitui regarding the future and violated his oath, e.g., he took an oath that he would not eat a loaf of bread and ate it, if he changes his mind, he may ask a sage to repeal it after eating it before bringing his sacrifice if he [ate it] inadvertently or before he was lashed if he did so willingly. [If the sage] releases the oath, he is exempt from the sacrifice or from the lashes. Moreover, even if they bound him [in preparation for lashes], he asked for the repeal of the oath and it was released before they began to administer lashes, he is exempt.50Once the court begins administering the lashes, the oath cannot be repealed (Radbaz).

הפלאה הלכות שבועות פרק ו
Haflaah Shevuos Chapter 6