Rashi on Numbers 30:14/רש"י על במדבר ל׳:י״ד

1כל נדר וכל שבעת אסר וגו׳ EVERY VOW AND EVERY BINDING OATH [TO AFFLICT THE SOUL HER HUSBAND MAY CONFIRM IT OR HER HUSBAND MAY ANNUL IT] — Because it states that a husband may annul his wife’s vows, one might think that all vows are implied! It therefore states: “[every vow] …to afflict the soul” — he may annul only vows to afflict the soul, and these are set forth in Treatise Nedarim 79b.