519—A free man may not be married to more than four women at once1, nor may a slave be married to more than two women at once2.

520—As for women possessed by his right hand, he may have intercourse with as many as he wishes.

521—If a disbeliever embraces Islam while he has two sisters as wives, he must choose one of them. If he has more than four wives, he must choose four and separate from the rest.

522—Also forbidden are:

1. A woman in the state of ihrām (ritual consecration), until she leaves that state.

2. A woman observing a waiting period after another husband, until the prescribed term is fulfilled.

3. A woman guilty of unlawful sexual intercourse, whether to the man with whom she committed it or to any other man, until she repents.

4. A wife whom a man has divorced three times is forbidden to him until she marries another husband, (who consummates the marriage with her and then separates from her) 3, and her waiting period expires.

523—It is permissible to own two sisters simultaneously. However, if he has intercourse with one of them, the other does not become lawful to him until he makes the first unlawful to himself by transferring her out of his ownership or arranging her marriage after establishing that she is not pregnant4.

524—The nursing that creates a marriage prohibition is that which occurs before weaning.