והתניא עד ראש חדש אדר עד ראש חדש אדר הראשון אם היתה שנה מעוברת עד ראש חדש אדר השני

And, so too, it is taught in a baraita:

If one vows until the New Moon of Adar, the vow remains in effect until the New Moon of the first Adar, and if it was a leap year, it remains in effect until the New Moon of the second Adar.

מכלל דרישא לאו במעוברת עסקינן שמע מינה הא דפשיטא ליה דמעברא שתא הא דלא ידע

The Gemara analyzes this baraita: Does the latter clause prove by inference that in the first clause, we are not dealing with a leap year? In a regular year there is only one month of Adar, so it is impossible to speak of a first or second Adar. Rather, learn from it that this latter clause is referring to a case where it is obvious to him that the year was extended, and therefore when he refers to the month of Adar he means the second Adar, whereas that first clause is referring to a case where he did not know that it was a leap year, in which case he means the first Adar.

מתני׳ רבי יהודה אומר קונם יין שאיני טועם עד שיהא הפסח לא נתכוון זה אלא עד ליל הפסח עד שעה שדרך בני אדם לשתות יין

MISHNA: Rabbi Yehuda says: In the case of one who says: Wine is konam for me, and for that reason I will not taste it until it will be Passover, it is understood that this individual intended for his vow to apply only until the night of Passover, i. e., until the time when it is customary for people to drink wine in order to fulfill the mitzva of drinking the four cups, but he did not intend to prevent himself from being able to fulfill this mitzva.

אמר קונם בשר שאיני טועם עד שיהא הצום אינו אסור אלא עד לילי צום שלא נתכוון זה אלא עד שעה שדרך בני אדם לאכול בשר רבי יוסי בנו אומר קונם שום שאני טועם עד שתהא שבת אינו אסור אלא עד לילי שבת שלא נתכוון זה אלא עד שעה שדרך בני אדם לאכול בשום

Similarly, if he said: Meat is konam for me, and for that reason I will not taste it until it will be the fast of Yom Kippur, he is prohibited from eating meat only until the eve of [leilei] the fast. This is because it is understood that this individual intended for his vow to apply only until the time when it is customary for people to eat meat in the festive meal before the fast, and he did not intend to prevent himself from being able to participate in that meal. Rabbi Yosei, his son, says: One who vows: Garlic is konam for me, and for that reason I will not taste it until it will be Shabbat, it is prohibited for him to eat garlic only until the eve of Shabbat, as it is understood that this individual intended for his vow to apply only until the time when it is customary for people to eat garlic.

האומר לחבירו קונם שאני נהנה לך אם אין את בא ונוטל לבניך כור אחד של חטין ושתי חביות של יין הרי זה יכול להפר את נדרו שלא על פי חכם ויאמר לו כלום אמרת אלא מפני כבודי זהו כבודי

In the case of one who says to another: Benefiting from you is konam for me, i. e., I am prohibited from deriving benefit from you, if you do not come and take for your son one kor of wheat and two barrels of wine as a gift, this other individual can dissolve his vow without the consent of a halakhic authority. This is because he can say to him: Did you say your vow for any reason other than due to my honor, in order to convince me to accept a gift for my son? This is my honor, that I refrain from accepting the gift, and consequently the vow is annulled.

וכן האומר לחבירו קונם שאת נהנית לי אם אין את בא ונותן לבני כור של חטין ושתי חביות של יין רבי מאיר אומר אסור עד שיתן וחכמים אומרים אף זה יכול להפר את נדרו שלא על פי חכם ויאמר לו הרי אני כאילו נתקבלתי

And, so too, in the case of one who says to another: Benefiting from me is konam for you, i. e., you are prohibited from deriving benefit from me, if you do not come and give my son one kor of wheat and two barrels of wine, Rabbi Meir says: It is prohibited for the other individual to benefit from the speaker until he gives the gifts to his son. However, the Rabbis say: Even this individual who took the vow can dissolve his own vow without the consent of a halakhic authority. This is because he can say to him: I hereby consider it as though I have received the gift.

היה מסרב בו לשאת בת אחותו ואמר קונם שהיא נהנית לי לעולם וכן המגרש את אשתו אומר קונם אשתי נהנית לי לעולם הרי אלו מותרות להנות לו שלא נתכוון זה אלא לשום אישות

If an individual was urging another to marry the daughter of his sister, and in order to deflect the pressure, the other man said: Benefiting from me is konam for her forever, i. e., she is prohibited from deriving any benefit from me forever, and, so too, if there is one who divorces his wife and says: Benefiting from me is konam for my wife forever, these women are permitted to derive benefit from him, as this man intended to take this vow only for the purpose of prohibiting marriage between them, but not to prohibit all forms of benefit.

היה מסרב בחבירו שיאכל אצלו אמר קונם לביתך שאני נכנס טיפת צונן שאני טועם לך מותר ליכנס לביתו ולשתות ממנו צונן שלא נתכוון זה אלא לשום אכילה ושתיה

Similarly, if one was urging another to eat with him, and the latter said: Entering your house is konam for me, as is tasting even a drop of cold liquid of yours, the individual who took the vow is nevertheless permitted to enter his house and to drink a cold beverage of his. This is because this individual intended to take this vow only for the purpose of eating and drinking a meal, but not to prohibit himself from entering the house entirely or from drinking in small quantities (Commentary on Nedarim ).

הדרן עלך קונם יין