Halacha

הלכה א
בִּנְּדָרִים הַלֵּךְ אַחַר לְשׁוֹן בְּנֵי אָדָם בְּאוֹתוֹ מָקוֹם וּבְאוֹתוֹ לָשׁוֹן וּבְאוֹתוֹ זְמַן שֶׁנָּדַר אוֹ נִשְׁבַּע בּוֹ. כֵּיצַד. נָדַר אוֹ נִשְׁבַּע מִן הַמְבֻשָּׁל. אִם דֶּרֶךְ אוֹתוֹ מָקוֹם בְּאוֹתוֹ לָשׁוֹן בְּאוֹתוֹ זְמַן שֶׁקּוֹרְאִין מְבֻשָּׁל אֲפִלּוּ לְצָלִי וּלְשָׁלוּק הֲרֵי זֶה אָסוּר בַּכּל. וְאִם אֵין דַּרְכָּם לִקְרוֹת מְבֻשָּׁל אֶלָּא לְבָשָׂר שֶׁנִּתְבַּשֵּׁל בְּמַיִם וּבְתַבְלִין הֲרֵי זֶה מֻתָּר בְּצָלִי וּבְשָׁלוּק. וְכֵן הַמְעֻשָּׁן וְהַמְבֻשָּׁל בְּחַמֵּי טְבֶרְיָא וְכַיּוֹצֵא בָּהֶן הוֹלְכִין בּוֹ אַחַר הַלָּשׁוֹן שֶׁל בְּנֵי הָעִיר:
כסף משנה
1.
With regard to vows, we follow the intent of the words people use at that place, in that language, and at that time when the vow or oath was taken.1The Rambam's rationale is that since everything depends on the person's intent, it is logical to assume that the meaning of his statements follows the usage common at that time and place. See also Halachah 13.
One might ask: If so, why in the halachot that follow does the Rambam set out guidelines with regard to vows. The Radbaz (in his gloss to Halachah 13) explains that these guidelines should be followed only in places where there is no clarity regarding the expressions commonly used.

What is implied? A person took a vow or an oath not [to partake of] cooked food. If it was customary in that place in that language and at that time to call roasted meat and boiled meat2I.e., boiled without spices (Rav Avraham MinHaHar). also cooked food, he is forbidden to partake of all types of cooked food. If they were accustomed to use the term cooked food only to refer to meat cooked with water and spices, he is permitted [to partake of] roasted meat or boiled meat. Similarly, with regard to smoked food or food cooked in the hot springs of Tiberias. We follow the terminology used by the people of that city.

הלכה ב
נָדַר אוֹ נִשְׁבַּע מִן הַמָּלִיחַ. אִם דַּרְכָּם לִקְרוֹת מָלִיחַ לְכָל הַמְּלוּחִין הֲרֵי זֶה אָסוּר בְּכָל הַמְּלוּחִין. וְאִם אֵין דַּרְכָּם לִקְרוֹת מָלִיחַ אֶלָּא לְדָג מָלִיחַ בִּלְבַד אֵינוֹ אָסוּר אֶלָּא בְּדָג מָלִיחַ:
כסף משנה
2.
[The following rules apply if a person] took a vow or an oath not to partake of salted foods. If it is customary to call all salted foods "salted food," he is forbidden to partake of all of them.3Although the Rambam's ruling runs contrary to the statements of the Mishnah (Nedarim 6:2), the Rambam relies on the principle that the determinant factor in values is the meaning attached to the terms used by people at that time and in that place. The Shulchan Aruch (Yoreh De'ah 217:3) follows the Rambam's approach. If it is customary to use the term "salted food" to refer only to salted fish, he is only forbidden to partake of salted fish.

הלכה ג
נָדַר אוֹ נִשְׁבַּע מִן הַכָּבוּשׁ אִם דַּרְכָּם לִקְרוֹת כָּבוּשׁ לְכָל הַכְּבוּשִׁים הֲרֵי זֶה אָסוּר בַּכּל. וְאִם אֵין דַּרְכָּם לִקְרוֹת כָּבוּשׁ אֶלָּא לְיָרָק כָּבוּשׁ בִּלְבַד אֵינוֹ אָסוּר אֶלָּא בְּכָבוּשׁ שֶׁל יָרָק. וְכֵן כָּל כַּיּוֹצֵא בָּזֶה:
כסף משנה
3.
[The following rules apply if a person] took a vow or an oath not to partake of pickled foods. If it is customary to call all pickled foods "pickled food," he is forbidden to partake of all of them.4Although the Rambam's ruling runs contrary to the statements of the Mishnah (Nedarim 6:2), the Rambam relies on the principle that the determinant factor in values is the meaning attached to the terms used by people at that time and in that place. The Shulchan Aruch (Yoreh De'ah 217:3) follows the Rambam's approach. If it is customary to use the term "pickled food" to refer only to pickled vegetables, he is only forbidden to partake of pickled vegetables. Similar laws apply in all analogous situations.

הלכה ד
הָיוּ מִקְצָת בְּנֵי הַמָּקוֹם קוֹרִין לוֹ כָּךְ וּמִקְצָתָם אֵין קוֹרִין אֵין הוֹלְכִין אַחַר הָרֹב אֶלָּא הֲרֵי זֶה סְפֵק נְדָרִים וְכָל סְפֵק נְדָרִים לְהַחְמִיר וְאִם עָבַר אֵינוֹ לוֹקֶה:
כסף משנה
4.
If some of the people would refer to food with one term and others would not use that term, we do not follow [the practice of] the majority. Instead, it is considered an unresolved question with regard to his vow. And whenever there is an unresolved question with regard to a vow, we rule stringently.5Since there is a possibility that a prohibition is involved, we must rule stringently. If one violates the vow, however, he is not liable for lashes.6For corporal punishment is inflicted only when we are certain that a prohibition has been violated.

הלכה ה
כֵּיצַד. נָדַר מִן הַשֶּׁמֶן בְּמָקוֹם שֶׁמִּסְתַּפְּקִין בְּשֶׁמֶן זַיִת וּבְשֶׁמֶן שֻׁמְשְׁמִין וְרֹב אַנְשֵׁי הַמָּקוֹם אֵין קוֹרִין שֶׁמֶן סְתָם אֶלָּא לְשֶׁמֶן זַיִת וְקוֹרִין לְשֶׁמֶן שֻׁמְשְׁמִין שֶׁמֶן שֻׁמְשְׁמִין וּמִעוּטָם קוֹרִין אַף לְשֶׁמֶן שֻׁמְשְׁמִין שֶׁמֶן סְתָם. הֲרֵי זֶה אָסוּר בִּשְׁנֵיהֶם וְאֵינוֹ לוֹקֶה עַל שֶׁמֶן שֻׁמְשְׁמִין. וְכֵן כָּל כַּיּוֹצֵא בָּזֶה:
כסף משנה
5.
What is implied? A person takes a vow [not to partake] of oil in a place where both olive oil and sesame seed oil are used. When most people from that place use the term "oil" without any modifier, they mean olive oil. When they refer to sesame seed oil, they call it "sesame seed oil." A minority of the populace, however, also refer to sesame seed oil with the term "oil" without a modifier. [Hence,] he is forbidden to partake of both of them, but is not liable for lashes for [partaking of] sesame seed oil. Similar laws apply in all analogous situations.

הלכה ו
כָּל דָּבָר שֶׁדֶּרֶךְ שָׁלִיחַ בְּאוֹתוֹ מָקוֹם לְהִמָּלֵךְ עָלָיו הֲרֵי הוּא בִּכְלַל הַמִּין שֶׁנֶּאֱמַר לְשָׁלִיחַ סְתָם. כֵּיצַד. מָקוֹם שֶׁדַּרְכָּן אִם יִשְׁלַח אָדָם שָׁלִיחַ לִקְנוֹת לוֹ בָּשָׂר סְתָם אָמַר לוֹ לֹא מָצָאתִי אֶלָּא דָּגִים אִם נִשְׁבַּע אוֹ נָדַר בְּמָקוֹם זֶה מִן הַבָּשָׂר נֶאֱסָר אַף בִּבְשַׂר דָּגִים. וְכֵן כָּל כַּיּוֹצֵא בָּזֶה. וּבְכָל מָקוֹם הַנּוֹדֵר מִן הַבָּשָׂר אָסוּר בִּבְשַׂר עוֹפוֹת וּבִקְרָבַיִם וּמֻתָּר בַּחֲגָבִים. וְאִם מַרְאִין הַדְּבָרִים בְּעֵת שֶׁנָּדַר שֶׁלֹּא נִתְכַּוֵּן אֶלָּא בִּבְשַׂר בְּהֵמָה בִּלְבַד [אוֹ לִבְשַׂר עוֹף וּבְהֵמָה בִּלְבַד] הֲרֵי זֶה מֻתָּר בִּבְשַׂר דָּגִים וַאֲפִלּוּ בְּמָקוֹם שֶׁהַשָּׁלִיחַ נִמְלַךְ עֲלֵיהֶן:
כסף משנה
6.
Whenever an agent in a given locale would have to question [the principal if that was his intent], it is considered in the category of the substance that was mentioned to the agent when [the term is mentioned] without a modifier.
What is implied? In a place where if a person would send an agent to buy meat without using a modifier to describe the term, the agent would tell him: "I found only fish [being sold],"7I.e., he is not certain whether the principal's intent when telling him to buy meat was to buy fish or not. [a person who took a vow not to partake of meat] is forbidden to partake of fish as well.8For in that locale, it is possible that it is referred to as "meat." Similar laws apply in all analogous situations.
In all places, a person who takes a vow [not to partake] of meat is forbidden to partake of fowl and of the entrails,9For they are generally referred to as meat. but is permitted to partake of grasshoppers.10For they are not. In the present age, this principle also applies to fish. The Rama (Yoreh De'ah 217:8) goes further and states that even fowl is not usually implied by the term "meat." If it appears that at the time he took the vow, his intent was only to forbid meat from an animal - or meat from an animal and fowl - he is permitted [to partake] of fish even in a place where an agent would question [if fish would be considered as meat].11The commentaries have noted that the Rambam's ruling is not entirely identical with that of his source (Nedarim 54a). In his Commentary to the Mishnah (Chullin 8:1), the Rambam explains this difficulty, stating that the meanings of terms used today are different than the meanings used for the same terms in the Talmudic period.

הלכה ז
הַנּוֹדֵר מִן הַמְבֻשָּׁל מֻתָּר בְּבֵיצָה שֶׁלֹּא נִתְבַּשְּׁלָה עַד שֶׁקָּפְתָּה אֶלָּא נִתְגַּלְגְּלָה בִּלְבַד. הַנּוֹדֵר מִמַּעֲשֵׂה קְדֵרָה אֵינוֹ אָסוּר אֶלָּא מִדְּבָרִים שֶׁמַּרְתִּיחִין אוֹתָן בִּקְדֵרָה. כְּגוֹן רִיפוֹת וּלְבִיבוֹת וְכַיּוֹצֵא בָּהֶן. אָסַר עַצְמוֹ מִכָּל הַיּוֹרֵד לִקְדֵרָה הֲרֵי זֶה אָסוּר בְּכָל הַמִּתְבַּשְּׁלִין בִּקְדֵרָה:
כסף משנה
7.
When a person takes a vow against partaking of cooked food, he is permitted to partake of an egg that has not been cooked until it hardens, but has merely been soft-boiled.12See the Rambam's Commentary to the Mishnah (Nedarim 6:1). When a person takes a vow [not to partake of food] boiled lightly in a pot,13This is the implication of the Hebrew term used by the Rambam [Bayit Chadash (Yoreh De'ah 217)]. he is only forbidden [to partake] of those foods that are boiled in a pot, e.g., groats, dumplings, and the like.14E.g., porridge (the Rambam's Commentary to the Mishnah, loc. cit.). See also Hilchot Berachot 3:4 which discusses these terms. If he forbade himself from partaking of anything placed in a pot, he is forbidden to partake of all food cooked in a pot.

הלכה ח
הַנּוֹדֵר מִן הַדָּגִים מֻתָּר בְּצִיר וּבְמֻרְיָס שֶׁל דָּגִים. הַנּוֹדֵר מִן הֶחָלָב מֻתָּר בַּקּוֹם וְהוּא הַמַּיִם הַמֻּבְדָּלִין מִן הֶחָלָב. נָדַר מִן הַקּוֹם מֻתָּר בְּחָלָב. נָדַר מִן הַגְּבִינָה אָסוּר בָּהּ בֵּין מְלוּחָה בֵּין תְּפֵלָה:
כסף משנה
8.
A person who vows [not to partake] of fish is permitted to partake of brine and a dip made with fish oil.15See the Rambam's Commentary to the Mishnah (Nedarim 6:3). A person who vows [not to partake] of milk is permitted to partake of the whey, i.e., the liquid that is separated from the milk. If he vows [not to partake] of whey, he is permitted to partake of milk. If he vows [not to partake] of cheese, he is forbidden to partake of both salted cheese and unsalted cheese.16In the Talmudic and Rabbinic era, most hard cheeses were salted to preserve them.

הלכה ט
הַנּוֹדֵר מִן הַחִטִּים אָסוּר בָּהֶן בֵּין חַיִּין בֵּין מְבֻשָּׁלִין. חִטָּה חִטִּים שֶׁאֲנִי טוֹעֵם אָסוּר בָּהֶן בֵּין קֶמַח בֵּין פַּת. חִטָּה שֶׁאֲנִי טוֹעֵם אָסוּר בְּאָפוּי וּמֻתָּר לָכֹס. חִטִּים שֶׁאֲנִי טוֹעֵם מֻתָּר בְּאָפוּי וְאָסוּר לָכֹס. חִטָּה חִטִּים שֶׁאֲנִי טוֹעֵם אָסוּר בֵּין בְּאָפוּי בֵּין לָכֹס. וְהַנּוֹדֵר מִן הַדָּגָן אוֹ מִן הַתְּבוּאָה אֵינוֹ אָסוּר אֶלָּא בַּחֲמֵשֶׁת הַמִּינִין:
כסף משנה
9.
A person who vows not to partake of grains of wheat is forbidden to partake of wheat kernels whether they are fresh or cooked. If he says: "Neither wheat, nor grains of wheat will I taste,"17The term chittim is plural, implying many kernels of grain. Chitah is singular, referring not to a single kernel, but rather to a single entity made from wheat flour (Rabbenu Nissim, as cited by the Kessef Mishneh). he is forbidden to partake of either flour or bread. "I will not taste wheat," he is forbidden to partake of baked goods, but permitted to chew kernels of wheat. If he states: "I will not partake of grains of wheat," he is permitted to partake of baked goods, but forbidden to chew kernels of wheat. If he says: "Neither wheat, nor grains of wheat will I taste," he is forbidden to partake of baked goods, nor may he chew kernels of wheat. When a person takes a vow forbidding himself from partaking of grain, he is forbidden only [to partake of] the five species.18I.e., wheat, barley, rye, oats, and spelt. Other grains, e.g., rice and millet, are not included.

הלכה י
הַנּוֹדֵר מִן הַיָּרָק מֻתָּר בִּדְלוּעִין. הַנּוֹדֵר בִּכְרֵישִׁין מֻתָּר בְּקַפְלוֹטוֹת. הַנּוֹדֵר מִן הַכְּרוּב אָסוּר בְּמַיִם שֶׁנִּתְבַּשֵּׁל בּוֹ הַכְּרוּב שֶׁהֲרֵי מֵי שְׁלָקוֹת כִּשְׁלָקוֹת. נָדַר מִמֵּי הַשְּׁלָקוֹת מֻתָּר בַּשְּׁלָקוֹת עַצְמָן. הַנּוֹדֵר מִן הָרֹטֶב מֻתָּר בַּתַּבְלִין שֶׁבּוֹ. מִן הַתַּבְלִין מֻתָּר בָּרֹטֶב. הַנּוֹדֵר מִן הַגְּרִיסִין אָסוּר בַּמִּקְפָּה שֶׁל גְּרִיסִין:
כסף משנה
10.
When a person takes a vow [not to partake of] green vegetables, he is permitted to partake of squash.19For in Talmudic terminology, the term green vegetable refers to vegetables that are eaten raw and squash must be cooked. If he takes a vow [not to partake of] leek, he is permitted to partake of the poret.20These two species of vegetables are similar, but not identical. Therefore, the Rambam feels it necessary to make this clarification. In his Commentary to the Mishnah (Nedarim 5:7), he uses the same Arabic term to define the two species but explains that the latter is more commonly grown in Eretz Yisrael.
If a person takes a vow [not to partake of] cabbage, he is forbidden to partake of the water cooked with cabbage, for the water in which food is cooked is considered as the food itself.21For through the cooking process, it takes on the flavor of the food (see Berachot 39a; Hilchot Berachot 8:4). In his Commentary to the Mishnah (Nedarim 5:8), the Rambam maintains that this is the meaning of the first clause of that mishnah. Rashi and others, while accepting this principle, interpret that clause differently. If, however, he vowed not to partake of the water in which a food is cooked, he may partake of the cooked food itself.22For there is obviously a difference between the food and the liquid in which it was cooked.
A person who takes a vow [not to partake of] sauce is permitted [to partake of] the spices. [One who takes a vow not to partake] of the spices is permitted [to partake of] the sauce. One who takes a vow [not to partake of] groats23I.e., ground beans (the Rambam's Commentary to the Mishnah, loc. cit.). is forbidden [to partake of] the thick sauce produced by the groats.24For it has the flavor of the groats.

הלכה יא
הַנּוֹדֵר מִן פֵּרוֹת הָאָרֶץ אָסוּר בְּכָל פֵּרוֹת הָאָרֶץ וּמֻתָּר בִּכְמֵהִין וּפִטְרִיּוֹת. וְאִם אָמַר כָּל גִּדּוּלֵי קַרְקַע עָלַי אָסוּר אַף בִּכְמֵהִין וּפִטְרִיּוֹת אַף עַל פִּי שֶׁאֵינָן יוֹנְקִין מִן הַקַּרְקַע גְּדֵלִין הֵן בַּקַּרְקַע:
כסף משנה
11.
A person who takes a vow [not to partake of] the produce of the earth is forbidden to partake of all the produce of the earth,25Not only vegetables, but fruit as well [Shulchan Aruch (Yoreh De'ah 217:23)]. but is permitted [to partake of] fungi and mushrooms.26Our Rabbis explain that the terms refer to species that have little botanical difference between them. The first term refers to those mushrooms which grow on the earth and the second, to those which grow in trees. The rationale is that, as the Rambam states, these fungi do not have roots. Thus they do not derive their nurture from the earth, but from the atmosphere (see Nedarim 55b; Hilchot Ma'aser Sheni 7:4). If he says: "Everything that grows upon the earth is [forbidden] to me," he is forbidden to partake of even fungi and mushrooms. [The rationale is that] although they do not derive their nurture from the earth, they grow upon the earth.

הלכה יב
הַנּוֹדֵר מִפֵּרוֹת הַשָּׁנָה אָסוּר בְּכָל פֵּרוֹת הַשָּׁנָה וּמֻתָּר בִּגְדָיִים וּבִטְלָאִים וּבְחָלָב וּבְבֵיצִים וּבְגוֹזָלוֹת. וְאִם אָמַר כָּל גִּדּוּלֵי שָׁנָה עָלַי אָסוּר בְּכֻלָּם. הַנּוֹדֵר מִפֵּרוֹת הַקַּיִץ אֵין אָסוּר אֶלָּא בִּתְאֵנִים:
כסף משנה
12.
When a person takes a vow forbidding himself from partaking of the produce of a particular year, he is forbidden to partake of all the produce of that year. He is, however, permitted to partake of kid-goats, lambs, milk, eggs, and, chicks.27The Hebrew word peirot can also be interpreted as: "benefit accruing from." Thus these entities could be included in the term. Nevertheless, since this is not the popular usage, they are not included. If, however, he said: "All of the products of a given year are [forbidden] to me," he is forbidden to partake of all of them.28The Siftei Cohen 217:31 explains that this applies only when it is possible for a person to abide by this prohibition. If, however, the vow prevents him from eating enough to maintain his wellbeing, it is nullified.
When a person takes a vow forbidding himself from partaking of the fruits of the kayitz, he is forbidden only to partake of figs.29The term kayitz has a specific meaning "fruit harvested by hand," rather than cut from the tree with a knife. Therefore, it refers to the fig harvest alone (Nedarim 61b).

הלכה יג
וּבְכָל הַדְּבָרִים הָאֵלּוּ וְכַיּוֹצֵא בָּהֶן הִזָּהֵר בְּעִקַּר הַגָּדוֹל שֶׁהוּא בִּנְדָרִים הַלֵּךְ אַחַר לְשׁוֹן בְּנֵי אָדָם שֶׁבְּאוֹתוֹ מָקוֹם בְּאוֹתוֹ לָשׁוֹן וּבְאוֹתוֹ זְמַן. וְעַל פִּי עִקָּר זֶה תּוֹרֶה וְתֹאמַר זֶה הַנּוֹדֵר אָסוּר בְּדָבָר פְּלוֹנִי וּמֻתָּר בְּדָבָר פְּלוֹנִי:
כסף משנה
13.
In all of the above - and in analogous instances - follow this general principle: With regard to vows, we follow the intent of the words people use at that place, in that language, and at that time when the vow or oath was taken.30As stated in Halachah 1. The Radbaz explains that the only reason the Rambam mentioned all the principles in the above and following halachot is to clarify the guidelines set forth by our Sages. They should be followed only in places where there is no clarity regarding the expressions commonly used. Based on this principle, one should rule and say: "The person who took the vow is forbidden [to benefit from] these entities and permitted [to benefit from] these entities."

הלכה יד
הַנּוֹדֵר מִן הָעֲנָבִים מֻתָּר בְּיַיִן וַאֲפִלּוּ הֶחָדָשׁ. מִן הַזֵּיתִים מֻתָּר בְּשֶׁמֶן. מִן הַתְּמָרִים מֻתָּר בִּדְבַשׁ תְּמָרִים. מִן הַסִּתְוָנִיּוֹת מֻתָּר בְּחֹמֶץ סִתְוָנִיּוֹת. מִן הַיַּיִן מֻתָּר בְּיֵין תַּפּוּחִים. מִן הַשֶּׁמֶן מֻתָּר בְּשֶׁמֶן שֻׁמְשְׁמִין. מִן הַדְּבַשׁ מֻתָּר בִּדְבַשׁ תְּמָרִים. מִן הַחֹמֶץ מֻתָּר בְּחֹמֶץ סִתְוָנִיּוֹת. מִן הַיָּרָק מֻתָּר בְּיַרְקוֹת שָׂדֶה. מִפְּנֵי שֶׁכָּל אֵלּוּ שֵׁם לְוַוי הֵם וְהוּא לֹא נָדַר אֶלָּא מִשֵּׁם שֶׁאֵינוֹ לְוַוי בְּאוֹתוֹ מָקוֹם. וְכֵן כָּל כַּיּוֹצֵא בָּזֶה:
כסף משנה
14.
When a person takes a vow [not to partake of grapes], he is permitted to partake of wine, even fresh wine.31Even though the wine tastes the same as grapes, since it is called by a different name, it is not considered in the same category (Siftei Cohen 216:27). This principle is reflected in all the rulings of this halachah: As long as an entity has a different name, even if its flavor is the same as another entity and even their substance is fundamentally the same, they are considered as different entities with regard to vows. [If he takes a vow not to partake] of olives, he is permitted to partake of oil. [If he takes a vow not to partake] of dates, he is permitted to partake of date-honey. [If he takes a vow not to partake] of grapes that blossom in the fall,32In his Commentary to the Mishnah (Nedarim 6:6) explains that these grapes are not fit to be eaten and instead, are used to produce vinegar. he is permitted to partake of vinegar that is produced from them.33The substances produced by the fruit are considered as being different from the fruit itself.
If he takes a vow not to partake] of wine, he is permitted to partake of apple wine. [If he takes a vow not to partake] of oil, he is permitted to partake of sesame seed oil. [If he takes a vow not to partake] of honey,34Although the Torah uses the term honey to refer to date-honey, in common usage, everyone understands the term as referring to bee honey (Siftei Cohen 217:22). he is permitted to partake of date honey. [If he takes a vow not to partake] of vinegar, he is permitted to partake of vinegar produced from grapes that blossom in the fall. [If he takes a vow not to partake] of vegetables, he is permitted to partake of vegetables that grow on their own.35The Siftei Cohen 217:15 states that in the present age, people do not make such a distinction when referring to these vegetables. [The rationale for all of these rulings is] that [the names of] all these substances have a modifier36I.e., they are not referred to by the name of the substance as it is used without a modifier. and [when] the person took the vow, he referred to the substance without a modifier. Similar laws apply in all analogous situations.

הלכה טו
הַנּוֹדֵר מִן הַכְּסוּת מֻתָּר בְּשַׂק וּבִירִיעָה וּבַחֲמִילָה. מִן הַבַּיִת אָסוּר בַּעֲלִיָּה שֶׁהָעֲלִיָּה בִּכְלַל הַבַּיִת. נָדַר מִן הָעֲלִיָּה מֻתָּר בַּבַּיִת. מִן הַדַּרְגָּשׁ מֻתָּר בַּמִּטָּה. מִן הַמִּטָּה אָסוּר בַּדַּרְגָּשׁ שֶׁהוּא כְּמוֹ מִטָּה קְטַנָּה:
כסף משנה
15.
When a person takes a vow not to wear clothing, he is permitted [to cover himself] with sackcloth,37This term refers to a weave from goat's hair (the Rambam's Commentary to the Mishnah, Nedarim 7:3). a coarsely woven thick fabric,38This translation is taken from the above source. a thick sheet used as a rainshield.39This translation is also taken from the above source. The rationale is that none of these fabrics are considered as garments.
[When a person takes a vow not to enter] a house, he is forbidden to enter its loft. For the loft is part of the house. [If he] takes a vow [not to enter] a loft, he is permitted [to enter] the home.
[When a person takes a vow not to] use a dargeish,40A small bed that is placed before a larger bed to use as a stepstool for the larger bed (the Rambam's Commentary to the Mishnah, Nedarim 7:4). he is permitted [to use] a bed. [If he takes a vow not to use] a bed, he is forbidden to use a dargeish, because it is like a small bed.

הלכה טז
הַנּוֹדֵר שֶׁלֹּא יִכָּנֵס לְבַיִת זֶה הֲרֵי זֶה אָסוּר מִן הָאֲגַף וְלִפְנִים. נָדַר שֶׁלֹּא יִכָּנֵס לְעִיר זוֹ מֻתָּר לְהִכָּנֵס לִתְחוּמָהּ וְאָסוּר לְהִכָּנֵס לְעִבּוּרָהּ:
כסף משנה
16.
When a person takes a vow not to enter a particular house, he is forbidden to enter from the doorframe onward. When one takes a vow not to enter a particular city, he is permitted to enter its Sabbath limits.41The area 2000 cubits around the city. See Hilchot Shabbat 27:1-2.
In other contexts, this area - and indeed, even further removed places - are considered as part of a city. With regard to vows, this is not the case, for we follow the terminology people commonly used (Siftei Cohen 217:35).
He is, however, forbidden to enter its outlying areas.42This term refers to homes that are located within 70 cubits of each other on the perimeter of the city. As long as they are within that distance of another home, they are considered as part of the city itself (Hilchot Shabbat 28:1; the Rambam's Commentary to the Mishnah, Nedarim, loc. cit.).
Nedarim 56b derives these concepts from the exegesis of Biblical verses. Joshua 5:13 states: "And while Joshua was in Jericho" and describes an event that took place while the Jews were camp on the outer reaches of the city. And when speaking about measuring the area 2000 cubits around a city, Numbers 35:5 speaks of measuring "outside the city."

הלכה יז
הַנּוֹדֵר הֲנָיָה מִבְּנֵי הָעִיר וּבָא אָדָם וְנִשְׁתַּהָה שָׁם שְׁנֵים עָשָׂר חֹדֶשׁ הֲרֵי זֶה אָסוּר לֵהָנוֹת מִמֶּנּוּ. פָּחוֹת מִכָּאן מֻתָּר. נָדַר מִיּוֹשְׁבֵי הָעִיר כָּל שֶׁשָּׁהָה שָׁם שְׁלֹשִׁים יוֹם אָסוּר לֵהָנוֹת מִמֶּנּוּ. פָּחוֹת מִכֵּן מֻתָּר:
כסף משנה
17.
When a person takes a vow not to benefit from the residents of a city and a person comes and lives there for twelve months, it is forbidden for the person who took the vow to benefit from him.43Note the parallel to Hilchot Shechenim 6:5 which states that a person who lives in a city for twelve months becomes obligated to pay all the city's levies. If he stays for a lesser time, it is permitted.
If he takes a vow from those who dwell in a city, he is forbidden to benefit from anyone who dwells there for 30 days. He is permitted to benefit from one who dwells there for a lesser period.44See the Rama (Yoreh De'ah 217:32) and the Siftei Cohen 217:37 who emphasizes that if the common terminology used at present is different, the laws are dependent on the current usages.

הלכה יח
הַנּוֹדֵר מִן הַמַּיִם הַנִּמְשָׁכִין מִמַּעְיָן פְּלוֹנִי. אָסוּר בְּכָל הַנְּהָרוֹת הַיּוֹנְקוֹת מִמֶּנּוּ וְאֵין צָרִיךְ לוֹמַר הַנִּמְשָׁכוֹת. אַף עַל פִּי שֶׁנִּשְׁתַּנָּה שְׁמָם וְאֵין קוֹרִין אוֹתָן אֶלָּא נָהָר פְּלוֹנִי וּבְאֵר פְּלוֹנִי וְאֵין מְלַוִּין אוֹתָן לְשֵׁם הַמַּעְיָן הַנָּדוּר הוֹאִיל וְהוּא עִקָּרָן אָסוּר בַּכּל. אֲבָל אִם נָדַר מִנָּהָר פְּלוֹנִי אוֹ מִמַּעְיָן פְּלוֹנִי אֵין אָסוּר אֶלָּא בְּכָל הַנְּהָרוֹת הַנִּקְרָאוֹת עַל שְׁמוֹ:
כסף משנה
18.
When a person takes a vow [not to benefit] from the water that flows from this-and-this spring, he is forbidden [to benefit] from all the rivers that derive nurture from it. Needless to say, this refers to those that flow directly from it. Although the name [of the body of water] has changed and it is now called "the So-and-So River" or "the So-and-So well," and we do not associate it at all with the name of the spring concerning which a vow was taken, since it is the source for these bodies of water, he is forbidden to benefit from all of them. If, however, a person takes a vow [not to benefit] from this-and-this river or spring, he is only forbidden [to benefit] from those rivers called by that name.

הלכה יט
הַנּוֹדֵר מִיּוֹרְדֵי הַיָּם מֻתָּר בְּיוֹשְׁבֵי הַיַּבָּשָׁה. מִיּוֹשְׁבֵי הַיַּבָּשָׁה אָסוּר בְּיוֹרְדֵי הַיָּם אַף עַל פִּי שֶׁהֵן מְפָרְשִׁים בְּאֶמְצַע הַיָּם הַגָּדוֹל. שֶׁיּוֹרְדֵי הַיָּם בִּכְלַל יוֹשְׁבֵי הַיַּבָּשָׁה. נָדַר מֵרוֹאֵי חַמָּה אָסוּר בְּסוּמִין שֶׁלֹּא נִתְכַּוֵּן זֶה אֶלָּא מִמִּי שֶׁהַחַמָּה רוֹאָה אוֹתוֹ. נָדַר מִשְּׁחוֹרֵי הָרֹאשׁ אָסוּר בְּקֵרְחִים וּבַעֲלֵי שֵׂיבוֹת וּמֻתָּר בְּנָשִׁים וּבִקְטַנִּים. וְאִם דַּרְכָּן לִקְרוֹת שְׁחוֹרֵי הָרֹאשׁ לַכּל אָסוּר בַּכּל:
כסף משנה
19.
When a person takes a vow not [to benefit] from sea-farers,45This term refers to people who set out on extended journeys, not on short jaunts. he is permitted [to benefit] from those who dwell on the land. When he takes a vow not [to benefit] from those who dwell on the land, he is forbidden [to benefit] from sea-farers even though they set out to the Mediterranean Sea. For sea-farers are considered as among those who dwell on land.46For they do not remain on an ocean journey forever and ultimately, return home.
When he takes a vow not [to benefit] from those who see the sun, he is forbidden to benefit from the blind.47Even though they cannot see the sun. For his intent was those who are seen by the sun. If he takes a vow not [to benefit] from those who are dark-haired, he is forbidden to benefit from men who are bald and grey-haired48For this term is generally used to refer to men, even if they do not have dark hair. and permitted to benefit from women49For they are referred to as being "covered-haired" (Rabbeinu Nissim). and children.50For they are referred to as being "uncovered-haired" (ibid.). If it customary to refer to all people as dark-haired, he is forbidden to benefit from everyone.

הלכה כ
נָדַר מִשּׁוֹבְתֵי שַׁבָּת אָסוּר בְּיִשְׂרָאֵל וּבְכוּתִים. נָדַר מֵעוֹלֵי יְרוּשָׁלַיִם אָסוּר בְּיִשְׂרָאֵל וּמֻתָּר בְּכוּתִים. שֶׁלֹּא נִתְכַּוֵּן זֶה אֶלָּא לְמִי שֶׁמִּצְוָה עָלָיו לַעֲלוֹת לִירוּשָׁלַיִם. וְהַנּוֹדֵר מִבְּנֵי נֹחַ מֻתָּר בְּיִשְׂרָאֵל שֶׁאֵין נִקְרָאִים בְּנֵי נֹחַ אֶלָּא שְׁאָר הָאֻמּוֹת:
כסף משנה
20.
When a person takes a vow not [to benefit] from those who rest on the Sabbath, he is forbidden [to benefit] from Jews and Samaritans.51This term refers to the people brought by the Assyrians to settle in Samaria after they exiled the Ten Tribes. At first, they converted and observed the rudiments of Judaism. Afterwards, however, they became like gentiles entirely. One who takes a vow not [to benefit] from those who make pilgrimages to Jerusalem is forbidden to benefit from the Jews and permitted to benefit from Samaritans. For his intent was to include only those for whom it is a mitzvah to make a pilgrimage to Jerusalem.52In his Commentary to the Mishnah (Nedarim 3:8), the Rambam explains that the Samaritans despise Jerusalem and make their pilgrimages to Mount Gerizim instead. The Merkevat HaMishnah explains that since the Samaritans are converts, they do not have a right to a portion in Eretz Yisrael. Hence they are not obligated to ascend to Jerusalem for the pilgrimage festivals (see Hilchot Ma'aser Sheni 11:15).
When one takes a vow not [to benefit] from the descendants of Noah, he is permitted to benefit from the Jews.53Although the Jews are also of Noah's descendants, they are not popularly referred to with that term. For the term "descendants of Noah" is used only to refer to members of other nations.

הלכה כא
נָדַר מִזֶּרַע אַבְרָהָם מֻתָּר בִּבְנֵי יִשְׁמָעֵאל וּבְנֵי עֵשָׂו וְאֵינוֹ אָסוּר אֶלָּא בְּיִשְׂרָאֵל. שֶׁנֶּאֱמַר (בראשית כא יב) "כִּי בְיִצְחָק יִקָּרֵא לְךָ זָרַע" וַהֲרֵי יִצְחָק אָמַר לְיַעֲקֹב (בראשית כח ד) "וְיִתֶּן לְךָ אֶת בִּרְכַּת אַבְרָהָם":
כסף משנה
21.
When a person takes a vow not [to benefit] from the descendants of Abraham, he is permitted [to benefit] from the descendants of Yishmael and the descendants of Esau.54Although actually, both of these nations descended from Abraham, Yishmael being Abraham's son and Esau, Isaac's. He is forbidden to benefit only from the Jews,55The Shulchan Aruch (Yoreh De'ah 217:40) states that this includes converts. as [indicated by Genesis 21:12]: "Through Isaac, your offspring will be called."56Thus excluding Yishmael and his descendants. And Isaac told Jacob [ibid. 28:4]: "And I will give you the blessing of Abraham."57Thus excluding Esau and his descendants. In his Commentary to the Mishnah (Nedarim 3:11), the Rambam adds another point. In the covenant God made with Abraham bein habetarim, he was told that his descendants would be "strangers in a foreign land" and only Jacob's descendants - not those of Esau or Yishmael - were subjected to this decree.

הלכה כב
נָדַר מִן הָעֲרֵלִים אָסוּר בְּמוּלֵי עַכּוּ''ם וּמֻתָּר בַּעֲרֵלֵי יִשְׂרָאֵל. נָדַר מִן הַמּוּלִים אָסוּר בְּעַרְלֵי יִשְׂרָאֵל וּמֻתָּר בְּמוּלֵי עַכּוּ''ם. שֶׁאֵין הָעָרְלָה קְרוּיָה אֶלָּא לְשֵׁם עַכּוּ''ם שֶׁנֶּאֱמַר (ירמיה ט כה) "כִּי כָל הַגּוֹיִם עֲרֵלִים" וְאֵין כַּוָּנָתוֹ שֶׁל זֶה אֶלָּא לְמִי שֶׁהוּא מְצֻוֶּה עַל הַמִּילָה וְלֹא לְמִי שֶׁאֵינוֹ מְצֻוֶּה עָלֶיהָ:
כסף משנה
22.
When a person takes a vow not [to benefit] from uncircumcised individuals, he is forbidden [to benefit] from circumcised gentiles,58This includes both gentiles who circumcise themselves for health reasons and those - like the Arabs - who circumcise themselves for religious reasons. The rationale is that the majority of gentiles and uncircumcised and the person made his statements with the intent of referring to the majority. See the Commentary of Rav Ovadiah of Bartenura to Nedarim, loc. cit. but is permitted [to benefit] from uncircumcised Jews. If he takes a vow not [to benefit] from circumcised individuals, he is forbidden [to benefit] from uncircumcised Jews, but is permitted [to benefit] from circumcised gentiles.
[The rationale is that] the foreskin is identified with the gentiles, as [Jeremiah 9:25] states: "For all the gentiles are uncircumcised. His intent is only to refer to those who are commanded concerning the circumcision and not to those who were not commanded concerning it.

הלכה כג
הַנּוֹדֵר מִיִּשְׂרָאֵל אָסוּר בְּגֵרִים. מִן הַגֵּרִים מֻתָּר בְּיִשְׂרָאֵל. הַנּוֹדֵר מִיִּשְׂרָאֵל אָסוּר בְּכֹהֲנִים וּלְוִיִּם. מִן הַכֹּהֲנִים וּמִן הַלְוִיִּם מֻתָּר בְּיִשְׂרָאֵל. הַנּוֹדֵר מִן הַכֹּהֲנִים מֻתָּר בִּלְוִיִּם. מֵהַלְוִיִּם מֻתָּר בְּכֹהֲנִים. הַנּוֹדֵר מִבָּנָיו מֻתָּר בִּבְנֵי בָּנָיו. וּבְכָל הַדְּבָרִים הָאֵלּוּ וְכַיּוֹצֵא בָּהֶן דִּין הַנּוֹדֵר וְהַנִּשְׁבָּע אֶחָד הוּא:
כסף משנה
23.
When a person takes a vow not [to benefit] from the Jewish people, he is forbidden [to benefit] from converts. [When a person takes a vow not to benefit] from converts, he is permitted [to benefit] from natural born Jews. When he takes a vow [not to benefit] from Israelites, he is forbidden [to benefit] from priests and Levites.59For when the term Israelite is used, it refers to the entire Jewish people as a collective. As Yoma 66a states: "Are not the priests part of Your nation Israel?" [When he vows not to benefit] from the priests and the Levites, he is permitted to benefit from an Israelite. [When he vows not to benefit] from the priests, he is permitted to benefit from the Levites.60Even though in the Torah, the priests are identified as Levites at times (Deuteronomy 17:9, et al), we follow the wording used by people at large (Radbaz). [When he vows not to benefit] from the Levites, he is permitted to benefit from the priests. [When he vows not to benefit] from his sons, he is permitted to benefit from his grandchildren.61Although Yevamot 62b states that grandchildren are considered as children, that is not the meaning employed by people at large (Radbaz). In all these and analogous matters, the laws regarding those who take a vow and an oath are the same.

הפלאה הלכות נדרים פרק ט
Haflaah Nedarim Chapter 9