Nedarim

Whence do we know it?  — Scripture states, If a man vow a vow unto the Lord:  This teaches that one must vow by what is [itself] forbidden through a vow.  If so, even [if one vows] by a [Divinely] interdicted object too, since it is written, to bind his soul with a bond?  — That is necessary for what was taught: Which is the bond referred to in the Torah etc. HE WHO SAYS TO HIS WIFE, BEHOLD! THOU ART UNTO ME AS MY MOTHER', etc. But a contradiction is shewn: If one says to his wife, 'Behold! thou art unto me as the flesh of my mother, as the flesh of my sister, as 'orlah,  as kil'ayim  of the vineyard, his words are of no effect.  — Said Abaye: His words are of no effect by Biblical law, yet absolution is required by Rabbinical law. Raba answered: One refers to a scholar; the other refers to an 'am haarez.  And it was taught even so: If one vows by the Torah,  his words are of no effect. Yet R. Johanan commented: He must retract [his vow] before a Sage; while R. Nahman observed: A scholar does not need absolution.