Prohibited Marriage Partners

Under the Shari'ah (Islamic Law), marriages
between men and women standing in a certain
relationship to one another are prohibited. These
prohibited degrees are either of a permanent
nature or a temporary. The permanently
prohibited degrees of marriage are laid down in
the Qur'an: "And marry not those women whom
your fathers married, except what has already
happened (of that nature) in the past. Lo! it was
ever lewdness and abomination, and an evil way.
Forbidden unto you are your mothers and your
daughters, and your sisters and your father's
sisters and your mother's sisters, and your
brother's daughters and your sister's daughters,
and your foster-mothers and your foster-sisters,
and your mothers-in-law and your step-
daughters who are under your mother-in-law and
your step-daughters who are under your
protection (born) of your women unto whom you
have gone into -- but if you have not gone into
them, then it is no sin for you (to marry their
daughters) -- and the wives of your sons from
your own loins, and that you should have two
sisters together, except what has already
happened (of that nature) in the past. Allah is
ever-Forgiving, Merciful. "
(Qur’an.Surah Nisa 4:22 - 24)
From the above Ayah, it is clear that a Muslim
must never marry the following:
His mother
His step-mother (this practice continues in
Yoruba land in Nigeria, where in some cases the
eldest son inherits the youngest wife of his
father)
His grandmother (including father's and mother's
mothers and all preceding mothers e.g. great
grandmothers )
His daughter (including granddaughters and
beyond )
His sister (whether full, consanguine or uterine)
His father's sisters (including paternal
grandfather's sisters)
His mother's sisters (including maternal
grandmother's sisters)
His brother's daughters
His foster mother
His foster mother's sister
His sister's daughter
His foster sister
His wife's mother
His step-daughter (i.e. a daughter by a former
husband of a woman he has married if the
marriage has been consummated. However, if
such a marriage was not consummated, there is
no prohibition)
His real son's wife
A great wisdom lies behind these prohibitions on
the grounds of consanguinity, affinity, and
fosterage. No social cohesion can exist if people
do not keep these prohibitions in their minds while
contracting marriages.
Temporary prohibitions are those which arise only
on account of certain special circumstances in
which the parties are placed. If the circumstances
change, the prohibition also disappears. They are
as follows:
A man must not have two sisters as wives at the
same time nor can he marry a girl and her aunt
at the same time.
A man must not marry a woman who is already
married. However this impediment is removed
immediately if the marriage is dissolved either by
the death of her former husband, or by divorce
followed by completion of the period of 'Iddah
(retreat or waiting period).
A man must not have more than four wives at
one time. This impediment is, of course, removed
as soon as one of the wives dies or is divorced.
A man must not marry a woman during her
'Iddah.