Islamic Sharia (body of Islamic laws) has established the interests of people in living and the hereafter, thus it combined the interest of the life and the afterlife. Since the texts of the Islamic sharia are infinite, the events are infinite. Therefore, the wisdom of Allah stipulated to endow the Sharia with certain characteristics that render then suitable for every time and every place.
The most important of these characteristics that is most flexible through which Sharia could comprehend all the newly occurring things is the necessity of jurisprudence in accordance with sharia policy rules in every issue of relevance to the lives of people. The jurisprudents have based these issues on sharia principles and rules that are deemed as the base of the hardening of the allowed which are going to discuss. According to the principle of deed consequences, the sent interest, and other principles. Undoubtedly, that period has occurred many social phenomena that relate the life of family and then society as whole. Therefore, dealing with these new things is the essence of maintaining the necessities which is through the intervention in these unprohibited things by obliging people to find solution to the new issues that were not stipulated about by the Legislator, like prohibiting the marriage between relatives because of genetic diseases in the family that effect negatively the new generation provided it is proven in medical examination. Therefore, the theme of this study is based on maintaining the general interests which is the basis that should be used in the policy of hardening the allowed. The conclusion comes up with the most important findings of the study and recommendations.