What should a wife do if her husband swore an oath upon her saying: "You are forbidden to me if you hide anything from me whatsoever," yet some matters of her life and her relationship with her family require confidentiality?

A husband does not have the right to divulge his wife's family secrets or the secrets of others, and she is not obliged to obey him in this, especially if such disclosure would lead to harm. However, if the secrets do not cause harm, it is permissible for the wife to inform her husband of them to avoid divorce (Talaq) or Zihar. Whether the husband breaks his oath if his wife conceals matters from him depends on his intention; if he intended to prevent her from concealing anything, he breaks his oath by the concealment of any matter. If he intended specific matters, he does not break his oath by the concealment of other matters. If the husband breaks his oath, the consequences depend on his intention behind the prohibition: if he intended Zihar, then it is Zihar; if he intended an irrevocable divorce (Talaq Bain), then it is an irrevocable divorce. Otherwise, it is a revocable divorce (Talaq Raj'i). If he intended an oath or did not intend anything, it is an oath that requires expiation. It is advisable to present the matter to trustworthy scholars for direct consultation.