What is this Pasuk coming to teach us about the Nedarim of an Arusah?
Rashi: It teaches us that if her betrothed endorses her Neder (by not annulling it on the day that he hears it) remains intact.
Targum Yonasan: It teaches us that if she declared a Neder after she married and her husband, endorses it on the day that he hears it, or is silent with the intention of endorsing it, 1 the Neder stands.
See Yayin ha'Tov, note 7.
What are the implications of "ve'Im be'Yom Shemo'a Iyshah Yani osah"?
Nedarim, 73a: It implies that if the Arus is deaf, he cannot annul the Arusah's Nedarim.
Sifri: It implies that silence on the day that the Arus hears it is akin to silence on the day that the Arusah declared the Neder.
