Dear Reb Tuvya,

Bigdei Tzivonim are attractive colorful clothes as opposed to the staid clothes of men which are typically shades of grey. From the Gemara in Pesachim (109a) we know that Bigdei Tzivonim are a source of Simchah for women. From the Gemara in Kesuvos (72b) we know that not wearing them is a source of Inu'i Nefesh for women. The Gemara gives other examples of Inu'i Nefesh - not eating meat and not drinking wine.

The Mishnah (ibid) says that if a woman has made a Neder of Inu'i Nefesh then she loses her Kesuvah if her husband divorces her. Why? The Gemara Shabbos (64b) says, in the name of R'Akiva, that women are allowed to wear Bigdei Tzivonim when they are a Nidah because if they do not, they risk being divorced by their husbands who will not find them attractive. Rashi says in Kesuvos (ibid) that if a woman doesn't eat meat her husband might find her unappealing.

Therefore it seems that Nidrei Inu'i Nefesh are just another example of things that Chazal considered an unstated breach of the marriage contract and therefore the woman loses her Kesuvah (other examples include certain situations where the woman does not want to move with her husband to his land (Shulchan Aruch E"H 75:1) or a woman who misleads her husband about her status a dah (E"H 115:2), etc.).

Kol Tuv,

Yonasan Sigler

This is not a Psak Halachah