Is it permissible for a woman to fast without informing her husband while she is visiting her family's home, especially if her husband is absent and does not inquire about her?

A woman is not permitted to observe a supererogatory fast unless her husband grants her permission, because fasting prevents him from enjoying her, and this is an immediate and obligatory right.

If the reason for the prohibition is absent, for example, if she knows that he has no need of her, then she is permitted to fast without his permission.

Some scholars hold that permission is required for frequent fasting, but not for infrequent fasting, and that her knowledge of his consent is equivalent to his permission. Therefore, there is no objection to her fasting if she is in her parents' home and her husband does not need her.