Is a woman's voluntary fast invalid if it is undertaken without her husband's permission, especially when she knows he will not have intercourse with her and he objects to her fasting merely out of rejection?

The basic principle is that a wife should not fast voluntarily while her husband is present unless with his permission, due to the magnitude of his right over her. If he does not need her, it is disliked for him to prevent her from fasting. If a woman fasts without her husband's permission, her fast is valid, though it is considered forbidden. A woman does not need her husband's permission if he is absent.

In the case where the husband has abandoned his wife and neglected her rights, and his prevention of her fasting is merely for the sake of domination, then the wife may fast even if she does not seek his permission.