Talmud - Nedarim 64a נדרים ס״ד א׳

MISHNA: Rabbi Eliezer says: When halakhic authorities are approached with regard to the dissolution of a vow, they may broach dissolution with a person who took a vow by raising the issue of how taking the vow ultimately degraded the honor of his father and mother, asking him the following: Had you known that your parents would experience public shame due to your lax attitude toward your vow, would you still have taken the vow? But the Rabbis disagree with Rabbi Eliezer and prohibit broaching dissolution of a vow with this particular question.

To support the opinion of the Rabbis, Rabbi Tzadok said: Instead of broaching dissolution with him by raising the issue of the honor of his father and mother, let them broach dissolution with him by raising the issue of the honor of the Omnipresent. They should point out that a vow taken in the name of God lessens the honor of God, so they could ask him: If you had known that your vow would diminish the honor of God, would you have taken your vow? And if so, if this is a valid method of broaching dissolution, there are no vows. Nevertheless, the Rabbis concede to Rabbi Eliezer with regard to a vow concerning a matter that is between him and his father and mother, that they may broach dissolution with him by raising the issue of the honor of his father and mother, as in this case the extenuation is connected to this particular vow.

And Rabbi Eliezer further said: They may broach dissolution by asking about a new situation, but the Rabbis prohibit it. How might they broach dissolution by asking about a new situation? If one said: It is forbidden to me like an offering [konam] that I will therefore not derive benefit from so-and-so, and that person later became a scribe [sofer], and the one who took the vow now requires his services, or if the one forbidden by the vow was marrying off his son and prepared a feast for all the residents of his town, and the one that had taken the vow said: Had I known that he would become a scribe, or that he would be marrying off his son in the near future, I would not have vowed.

The mishna cites another example of a new situation. If one said: Entering this house is konam for me, and that house became a synagogue, and he said: Had I known that it would become a synagogue, I would not have vowed, in this and all such cases Rabbi Eliezer permits the halakhic authority to use this as a basis for the dissolution of the vow, and the Rabbis prohibit it.

GEMARA: The Gemara clarifies the meaning of the statement made by Rabbi Tzadok. What does: If so, there are no vows, mean? Abaye said: It means: If so, vows are not dissolved properly. The one who took the vow might say he regrets doing so only because he is not willing to publicly state that he would have taken his vow despite knowing that it diminishes the honor of God. He may not actually regret having taken the vow, and this will lead to the improper dissolution of the vow.

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Nedarim 64a examines Rabbi Eliezer's and the Rabbis' debate over dissolving vows through parental honor or unforeseen new circumstances.