What is the difference between impotence (al-innah) and mutual imprecation (al-mula'anah)? What is the ruling on the one who curses (al-la'in) in Islam? And is cursing one's wife considered a divorce?

Innah (impotence) is the inability to have sexual intercourse. As for li'an (oath of condemnation), linguistically it means expulsion and banishment. Religiously, it refers to specific words used as a proof for the accuser whose bed has been defiled, or to deny the paternity of a child. It is called so because it includes the word 'curse' (la'n), and because it distances the spouses from each other, permanently prohibiting marriage between them.

Its procedure: The husband says four times: "I bear witness by Allah that I am among the truthful in what I have accused her of regarding adultery." And for the fifth time: "May the curse of Allah be upon him if he is among the liars in what he has accused her of regarding adultery." He also swears to deny the child's paternity if it resulted from adultery.

As for the wife, she says four times: "I bear witness by Allah that he is among the liars in what he has accused me of regarding adultery." And for the fifth time: "May the wrath of Allah be upon her if he is among the truthful in what he has accused me of regarding adultery."

Li'an may be obligatory for the husband if he is certain that the pregnancy is not from him, in order to deny the child's paternity.