Verses 22-25 of Chapter 4:
And do not marry at
all those women whom your father had married though what has happened
in the past is excepted. This is an indecent and abominable thing and an evil
practice. Forbidden to you
are your mothers, daughters, sisters, paternal aunts, maternal aunts, brother's daughters, sister's
daughters,
your foster mothers who have given a suckle to you, your
foster sisters,
who have taken suckle with you, the mothers of your wives,
the daughters of your wives whom you have brought up,
the daughters of those wives with whom you have had conjugal
relations, but not of those wives with whom you have had no conjugal
relations, and it is not sinful for you to marry their daughters
(after having divorced them); and also forbidden to you are the wives
of your sons who are from your loins,
and it is unlawful for you to keep two real sisters as wives
at one and the same time, hough what happened in the past is excepted, for Allah is
indeed Forgiving, Merciful.
And forbidden to you are the wedded wives of other people
except those who have fallen in your hands (as prisoners of war): this is the Law of Allah that has been prescribed for you.
With the exception of the above, it has been made lawful for you to
seek in marriage with your wealth any other women provided that you
keep them in wedlock and not in licentiousness. Then you should pay
them their dowries as an obligation for the enjoyment of conjugal
relations with them. However, there is no harm if a compromise is
made in the dower by mutual consent after an agreement about it;
Allah is All-Knowing, All Wise. Whoever cannot
afford to marry free Muslim women, should marry one of the Muslim
slave-girls in your possession; Allah has full knowledge of your
Faith. You all belong to one and the same community;
therefore, you may marry them with the permission of their
guardians and give them their fair dowries so that they may live a
decent life in wedlock and not in licentiousness nor may have secret
illicit relations. Then if they are guilty of indecency, after they
have been fortified by wedlock, they shall be given half the
punishment prescribed for free women.
This concession
has been made for those of you who might apprehend a moral
lapse without marriage, but it is better for you to practice
self-restraint, and Allah is Forgiving, Merciful.