Fathwa, - Is it permissible for a man to marry his wife's stepmother?

Question:
Is it permissible for a man to marry his wife's stepmother? Man A is
married to Woman B, whose father has four wives, one of whom (Woman C)
is 3 years older than Woman B. Woman B's father (i.e. Woman C's
husband) dies, and Man A marries Woman B's stepmother, i.e. Woman C.
Is this permissible?
Answer:
The nature of Shariah is such that it intends to eradicate anything
that may lead to the breaking of ties and disputes. In many
injunctions of Shariah, we see that the main cause behind the
prohibition of a certain act is the possibility of disputes and
arguments arising. Many laws of commerce and trade are based on this
very principle.
Due to this, it was prohibited for a man to combine two or more women
in his marriage (i.e. at the same time) who are closely related to
each other. Co-wives normally and naturally become jealous of each
other and not everything is hunky-dory between them, thus the idea
behind the prevention of combining two relatives in marriage is to
prevent the breaking of ties between relatives and closely related
people.
The great Hanafi jurist (faqih), Imam Ibn Abidin (Allah have mercy on
him) explains:
"...Combining them (closely related women) in marriage is unlawful
(haram) due to the reason that it will normally lead to the breaking
of ties between the co-wives who are related. And the evidence for
this is the Hadith recorded by al-Tabrani that the Messenger of Allah
(Allah bless him & give him peace) said: "If you do that (m: i.e.
combine two related women in marriage), you will be breaking ties" and
more details is mentioned in Fath al-Qadir." (Radd al-Muhtar, 3/36)
Thus, the Qur'an prohibited the combining of two sisters in marriage.
Allah Most High states:
"Prohibited to you (for marriage) are......two sisters in wedlock at
one and the same time." (Surah al-Nisa, 23)
Similarly, Sayyiduna Abu Hurayra (Allah be pleased with him) narrates
that the Messenger of Allah (Allah bless him & give him peace) said:
"A woman and her paternal aunt must not be combined in marriage,
neither a woman and her maternal aunt." (Sahih al-Bukhari, no. 4820)
Based on the above, the Hanafi jurists (fuqaha) have laid down a
principle with regards to the prohibition of combining two women in
marriage which is that, it is not permissible to combine two women who
are such that, if one of them were a man, it would not be permissible
for her to marry the other.
It is stated in al-Fatawa al-Hindiyya:
"The principle (asl) is that it will not be permissible to combine two
women (in marriage) who are such that if one of them was presumed to
be a man, from any side, then it would not be permissible for them to
marry each other." (al-Fatawa al-Hindiyya, 1/277)
Imam al-Haskafi (Allah have mercy on him) states:
"It is unlawful to combine two women (in marriage) who are such that
if one of them was presumed to be a man, it would not be permissible
for him (her) to marry the other." (See: Radd al-Muhtar ala al-Durr,
3/38)
The meaning of the above two texts is that, Allah Most High has
mentioned the list of people whom it is unlawful for one to marry,
such as one's sister, mother, daughter, aunt, niece, mother in-law,
wife's daughter, etc. Thus, if one intends to combine two women in
marriage, one must look at whether, if one of them was assumed to be a
man, it would be permissible for her (him) to marry the other? If not,
then it would be unlawful to combine them in marriage. This assumption
must be from both sides, as mentioned in the text of al-Fatawa
al-Hindiyya, where it stated "from any side".
For example, there are two sisters, and a person wants to combine them
in marriage. Now, if we presume any one of them to be a man, marriage
would be unlawful between them. The reason being is that if any one of
them was presumed to be a man, he will be the brother of the other,
and marriage with one's sister is unlawful. This will be the case
regardless of whom we presume to be a man, i.e. from both sides.
Having understood the above, we come to the question of marrying one's
stepmother in-law. To combine a woman and her real mother (i.e. real
mother in-law) in marriage is without doubt unlawful, for if any one
of them were to be a man, marriage would not be lawful between them.
Let's say the mother was a man. In this situation it will be unlawful
for a father to marry his own daughter. Suppose we considered the
daughter to be a man, even in this case, it is unlawful for a son to
marry his mother. Thus, to have a daughter and her (real mother) in
marriage at the same time is unlawful.
However, the case with combing a woman and her step-mother is not the
same, in that this is permissible. The reason here is that, if we
presumed the daughter to be a man, then indeed it will not be
permissible for a man to marry his step-mother. However, in the vice
versa situation, meaning if we presumed the mother to be a man, it
will be allowed for him to marry the girl. The women will not be
considered to be a step father marrying his daughter, rather a strange
(ajnabi) man marrying a girl, for we presumed her to be man, thus she
cannot be the wife of her husband (I hope this is understandable!).
Thus, the Hanafi Fuqaha have permitted the marriage to a woman and her
stepdaughter at the same time. It is stated in al-Fatawa al-Hindiyya:
"It will be permissible to combine (in marriage) a woman and her
husband's daughter (m: from another wife), because if the women (m:
mother) was presumed to be a man, it would be permissible for him to
marry the girl. However, in the vice versa situation, it would not be
allowed." (al-Fatawa al-Hindiyya, 1/277)
Imam al-Haskafi (Allah have mercy on him) states:
"It is permissible to combine (in marriage) a woman and her husband's
daughter (m: i.e. a girl and her stepmother)."
Imam Ibn Abidin (Allah have mercy on him) explains the above by stating:
"...Because if the woman (mother) was presumed to be a man, he will be
marrying the husband's daughter, and she (the daughter) will be
considered to be a daughter of a strange man (m: meaning, she cannot
be classed as a man and also have a husband at the same time, thus one
will have to say that her relationship with the girl is that of a
stranger." (Radd al-Muhtar, 3/39)
In conclusion, it is permitted for a man to combine a woman and her
stepmother in marriage at the same time, or in other words, a woman
and her stepdaughter. Thus, marriage with a stepmother in-Law is
perfectly permissible whether separately or with keeping her
stepdaughter in the marriage.
And Allah knows best.