נדרים ט׳Nedarim 9

Mishnah 1א׳

רַבִּי אֱלִיעֶזֶר אוֹמֵר, פּוֹתְחִין לָאָדָם בִּכְבוֹד אָבִיו וְאִמּוֹ. וַחֲכָמִים אוֹסְרִין. אָמַר רַבִּי צָדוֹק, עַד שֶׁפּוֹתְחִין לוֹ בִכְבוֹד אָבִיו וְאִמּוֹ, יִפְתְּחוּ לוֹ בִכְבוֹד הַמָּקוֹם, אִם כֵּן אֵין נְדָרִים. וּמוֹדִים חֲכָמִים לְרַבִּי אֱלִיעֶזֶר בְּדָבָר שֶׁבֵּינוֹ לְבֵין אָבִיו וְאִמּוֹ, שֶׁפּוֹתְחִין לוֹ בִּכְבוֹד אָבִיו וְאִמּוֹ:

Rabbi Eliezer says, we give a person an opening [to a vow] by reference to the honor of their father and mother. The Sages forbid doing so. Rabbi Tzadok said, that rather than giving an opening through the honor of their father and mother, open with honor of God. [The Sages retort:] If so there would be no vows! The Sages agree to Rabbi Eliezer in a matter between him and his father and mother, that we may open with the honor of his father and mother.

Mishnah 2ב׳

וְעוֹד אָמַר רַבִּי אֱלִיעֶזֶר, פּוֹתְחִין בְּנוֹלָד. וַחֲכָמִים אוֹסְרִין. כֵּיצַד. אָמַר, קוֹנָם שֶׁאֵינִי נֶהֱנֶה לְאִישׁ פְּלוֹנִי, וְנַעֲשָׂה סוֹפֵר, אוֹ שֶׁהָיָה מַשִּׂיא אֶת בְּנוֹ בְקָרוֹב, וְאָמַר, אִלּוּ הָיִיתִי יוֹדֵעַ שֶׁהוּא נַעֲשֶׂה סוֹפֵר אוֹ שֶׁהוּא מַשִּׂיא אֶת בְּנוֹ בְקָרוֹב, לֹא הָיִיתִי נוֹדֵר. קוֹנָם לְבַיִת זֶה שֶׁאֵינִי נִכְנָס, וְנַעֲשָׂה בֵית הַכְּנֶסֶת, וְאָמַר, אִלּוּ הָיִיתִי יוֹדֵעַ שֶׁהוּא נַעֲשֶׂה בֵית הַכְּנֶסֶת לֹא הָיִיתִי נוֹדֵר, רַבִּי אֱלִיעֶזֶר מַתִּיר, וַחֲכָמִים אוֹסְרִין:

And furthermore Rabbi Eliezer said: They make an opening for a vow by reference to a new fact; but the Sages forbid it. How so? He said, “Konam that I will not benefit from so and so,” and he [the latter] then became a scribe, or was about to give his son in marriage, and he said, “Had I known that he would become a scribe or was about to give his son in marriage, I would not have vowed;” [Or if he said,] “Konam, is this house that I will not enter,” and it became a synagogue, and he declared, “Had I known that it would become a synagogue, I would not have vowed,”—Rabbi Eliezer permits [the vow to be released], but the Sages forbid it.