Reference for Nedarim 47:4
תא שמע האומר לחבירו קונם שאתה נהנית לי אם אי אתה נותן לבני כור של חיטין ושתי חביות של יין רבי מאיר אומר עד שיתן וחכמים אומרים אף זה יכול להתיר את נדרו שלא על פי חכם שיכול לומר הריני כאילו התקבלתי
Come and hear: If one says to his neighbour, 'Konam that you benefit not from me, if you do not give my son a <i>kor</i> of wheat and two barrels of wine,' — R. Meir rules: He is [so] forbidden until he gives; but the Rabbis maintain: He too can annul his vow without a Sage by declaring: 'I regard it as though I have received it.' Thus, it is only because he says, 'I regard it as though I have received it'; but otherwise it is [a valid] vow. Whose view is this? If R. Eliezer b. Jacob's, — but it is a vow of incitement. Hence it must be the Rabbis'; thus proving that they disagree with him! — [No.] Verily, it may be R. Eliezer b. Jacob's view: he admits that this is a [real] vow, for he [who makes it] says, 'I am not a king to benefit you without your benefiting me.'