Reference for Nedarim 30:11

באומר הנאת תשמישך עלי והא לא קא ניחא ליה בתשמיש

— It means that he vows, 'The pleasure of cohabitation with you be forbidden me': thus he surely denies himself the enjoyment of cohabitation.<span class="x" onmousemove="('comment',' Hence his vow is valid, since it falls primarily upon himself. ');">⁸</span>

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