What is this Pasuk coming to teach us that we do not already know?
Rashi: It is coming to confine the husband's mandate to annul his wife's Nedarim, to those that cause her pain.
Rashi: As listed in Nedarim, 79a. See for example, Ramban (citing Tosefta), Torah Temimah, 78 and Ba'al ha'Turim. Refer also to 30:17:1:1.