Is it permissible to stipulate that the wife be divorced if the husband does not join her within a certain period, and does the divorce take effect merely upon the expiration of that period? And is it permissible for the wife to stipulate that the marital bond be in her hand, or to link it to a condition of divorce after a certain period?

It is permissible for a woman to stipulate in the marriage contract that she can divorce herself if her husband marries another, or if he is absent from her, or if he harms her. This is the fatwa given by Ibn Abd al-Barr, Shaykh al-Islam Ibn Taymiyyah, and Ibn al-Qayyim. This condition is valid and binding on the husband. Based on this, it is permissible for a woman to stipulate in the contract with her husband that if he does not join her within a specified period, she has the right to divorce herself. Divorce does not occur merely by the passage of time; rather, the woman must initiate it. If the laws permit this condition, that is sufficient for the woman to preserve her rights, and it is not permissible for her to stipulate that the marital authority (ismah) be in her hand. If the laws do not permit the first condition but allow the marital authority to be in her hand, then we hope that there is no sin upon her in stipulating that, provided she does not use this condition except in the agreed-upon scenario, which is the husband's delay in joining her.