dhihar

Dhihar is a type of divorce which was common in pre-Islamic Arabia, but was made unlawful by Islam. It was a way when the husband wanted to divorce his wife he would selfishly say to her, "You are like my mother." This way she would have not conjugal rights, but at the same time she would still be bound to him like a slave. See Holy Qur'an, Al-Ahzab (33:4), Mujadilah (58:1-5).