forbidden with choice (الْحَرَامُ الْمَخَيّر)
أصول الفقه
التعريف :
This is the case where God has issued a prohibition that applies to one of several equal things. This is the subject of different views. One example of this is the case of a person who embraces Islam but he is married to two sisters. Under Islamic shariah a Muslim may not marry two sisters at the same time. He must choose one of them to remain his wife and the other becomes forbidden to him.