9 “Any vow or obligation taken by a widow or divorced woman will be binding on her.

Read Numbers 30:9 Using Other Translations

But every vow of a widow, and of her that is divorced, wherewith they have bound their souls, shall stand against her.
(But any vow of a widow or of a divorced woman, anything by which she has bound herself, shall stand against her.)
If, however, a woman is a widow or is divorced, she must fulfill all her vows and pledges.