Shevuot 20B

אלא לרבא קשיא!

But according to Rava’s opinion, that association with an oath is not considered an oath, the baraita poses a difficulty, as it indicates that association with a vow is considered a vow; a corresponding rule should apply to an oath.

אמר לך רבא, תריץ ואימא הכי: איזהו איסר נדר האמור בתורה? האומר: ״הרי עלי שלא אוכל בשר ושלא אשתה יין״ כיום שמת בו אביו, כיום שנהרג בו פלוני. ואמר שמואל: והוא שנדור ובא מאותו היום.

The Talmud answers: Rava could say to you: Resolve the difficulty posed by the baraita and say that the baraita teaches this: Which is the bond of a vow mentioned in the Torah? When is a bond, i.e., the acceptance of a prohibition on oneself, considered a vow? According to Rava, “bond” in the verse is not referring to association. Rather, it is referring to one who says: It is incumbent upon me that I will not eat meat and that I will not drink wine like on the day that his, i.e., my, father died, or: Like on the day that so-and-so was killed. And Shmuel says: This is the halakha only when he is prohibited from eating meat and drinking wine by vow since that day, e.g., the day his father died.

מאי טעמא? אמר קרא: ״איש כי ידר נדר לה׳״⁠ – עד שידור בדבר הנדור.

What is the reason for Shmuel’s caveat? The verse states: “When a man vows a vow to YHWH” (Numbers 30:3). The redundancy in the phrase “vows a vow” teaches that when one associates a vow with another prohibition, it does not take effect unless he vows by associating it with an item forbidden by means of a vow. Association is derived from this verse and is limited to vows.

כיום שמת בו אביו. פשיטא! כיום שנהרג בו גדליה בן אחיקם איצטריך ליה, סלקא דעתך אמינא: כיון דכי לא נדר נמי אסור ⁠– כי נדר נמי לא הויא עליה איסור, והאי לאו מיתפיס בנדר הוא; קא משמע לן.

The Talmud discusses the baraita: One who says: It is incumbent upon me that I will not eat meat and that I will not drink wine like on the day that his father died. The Talmud asks: Isn’t it obvious that he is prohibited from eating meat and drinking wine? Why does the baraita need to mention the specific example of a vow concerning the day his father died? The Talmud answers: It was necessary that the baraita state that the vow takes effect for the sake of the other example: Like on the day that Gedaliah ben Ahikam was killed. Otherwise, it may enter your mind to say: Since, even if he did not vow to refrain from eating meat or drinking wine on that day they would be prohibited to him anyway, as it is a public fast day, when he did vow to refrain from eating and drinking on that day, the prohibition of the vow would not take effect on him, and that subsequent vow would then not be associated with a vow, but with an ordinary prohibition. Therefore, the baraita teaches us that the vow made on the fast day takes effect and the second vow can be associated with it.