What is the ruling of the Sharia regarding a father preventing his daughter from returning to her husband’s house, and demanding a divorce without a valid reason, and what is the punishment for one who does so, and what should I do about the wife's mother's continuous incitement against her?

A wife is Islamically obligated to obey her husband in what is reasonable, and her obedience to him takes precedence over her obedience to her parents. It is forbidden for her to leave her home without his permission, unless there is a legitimate Islamic justification.

If the wife leaves to seek independent housing, this is one of her rights. However, her leaving for a wedding party or due to her mother's instigation is not her right. Her parents' intervention by inciting her to divorce is a grave wrongdoing, as the Messenger of Allah, peace and blessings be upon him, said: "He is not one of us who instigates a woman against her husband."

We recommend continuing on the path of reconciliation, acting upon the words of Allah the Almighty: "And if a woman fears from her husband nushuz (ill-conduct or desertion) or aversion, there is no sin upon them if they make terms of settlement between them, and settlement is best." If reconciliation is not achieved, separation may be better, as divorce can remove the corruption resulting from the continuation of the marriage.

If the husband is not the one harming the wife, he has the right to refuse divorcing her until she ransoms herself from him.

As for custody while the marriage is ongoing, it is a right for both parents. Upon separation, the mother has a greater right to custody unless there is an impediment. The party with custody is not allowed to prevent the other party from seeing and visiting the child.