What is the ruling on a wife praying for her husband's second marriage not to be successful, and what is the ruling on his refusal to treat his wife for infertility, this being after he violated a previous agreement that the second wife would live in a separate residence, and he insists on her living in the same house with the first wife, threatening her with divorce?

The foundation of the marital relationship is good companionship. What the husband does in terms of injustice and ill-treatment is contrary to Islamic law, and he must desist from it. The wife has the right to a private dwelling, and if she stipulated this, then fulfilling it becomes obligatory. There is no harm in the wife supplicating against her husband if he is unjust. The wife's medical treatment is an obligation upon her husband, and he must not deprive her of the right to procreation.