The scholars are in agreement that no man is allowed to marry a woman who is married to another man until this wedlock ceases to exist through separation, divorce, or the passing of her husband. The consensus has been transmitted by al-Shafi’i, Ibn Taymiyyah, and al-Shirbeenee.

The scholars are in agreement that it is forbidden to marry a woman during her divorce waiting period or during the waiting period she is observing due to the death of her husband. The consensus has been transmitted by Ibn Hazm and Ibn Taymiyyah.

It is forbidden for a man to marry a woman while he is married to four wives at the same time. However, it becomes permissible for him to marry a new woman if one of his wives passes away or he divorces one of them, provided her waiting period has expired. The consensus on this ruling has been transmitted by Ibn al-Munthir, Ibn Hazm, al-Qurtubee, and al-Zarkashee.

It is forbidden for a man to remarry the woman whom he has divorced three times unless she has married someone else and divorced afterwards, provided intercourse with her new husband has taken place and her new divorce waiting period has expired. [49] This will be discussed in more details in the Chapter of Divorce – Section 4: Types of Divorce: The possibility to remarry one’s own divorcee.

The scholars are in agreement that it is forbidden for a man to marry his wife’s sister, paternal aunt, or maternal aunt at the same time. The consensus on this ruling has been transmitted by Ibn al-Munthir, Ibn ‘Abd al-Barr, and Ibn Taymiyyah.

The majority of scholars hold the view that it is not permissible for a man to marry a woman while she is in the state of Ihraam for Hajj or ‘Umrah. According to the Maliki, Shafi’i and Hanbali Madhabs, the marriage in such a case is deemed invalid. This is also the view of the Dhahiri scholars, the majority of scholars from the Companions and Tabi’een, and it is a matter of agreement between the people of al-Madeenah.

7. Marrying an adulteress:
a. Her repentance from adultery and fornication is a prerequisite: It is forbidden for a man to marry an adulteress if he has not repented from adultery and fornication. This is the view of the Hanbali Madhab, the view of a group from the righteous predecessors, and the view of Ibn Hazm, Ibn Taymiyyah, Ibn al-Qayyim, al-Shanqeetee, Ibn ‘Uthaymeen, and the Permanent Committee.
b. Evidence of no pregnancy: It is not permissible to marry an adulteress until after establishing that there was no pregnancy by waiting for one menstrual cycle. This is one of the reported views of Imam Ahmad, the view of In Taymiyyah, Ibn al-Qayyim, Ibn Baaz, Ibn ‘Uthaymeen, and the Permanent Committee.  

The scholars agree that it is forbidden for the Muslim man to marry a disbelieving woman who is not from the People of the Book, i.e. she is neither Christian nor Jewish until she becomes Muslim. This consensus has been transmitted by al-Shafi’i and Ibn ‘Abd al-Barr.