Why did the Prophet (PBUH) forbid ʿAlī [may Allāh be pleased with him] from marrying any woman besides Fāṭimah [may Allāh be pleased with her]?

ʿAlī ibn Ḥusayn reported that al-Miswar ibn Makhramah told him that ʿAlī ibn abī Ṭālib had proposed to the daughter of abū Jahl while Fāṭimah, the daughter of the Messenger of Allāh (PBUH), was with him (i.e., his wife). When Fāṭimah heard of this, she went to the Prophet (PBUH) and said to him, “Your people are saying that you do not become angry for the sake of your daughters, and this is ʿAlī marrying the daughter of abū Jahl.” Al-Miswar said: “The Prophet (PBUH) stood up, and I heard him when he made tashahhud (i.e., bore witness that there is none worthy of worship but Allāh, and that Muḥammad is His Messenger), and then he said: “To proceed: I have married my daughter [Zaynab] off to abū al-ʿĀṣ ibn ar-Rabīʿ and he spoke with me and he was truthful to me [whatever he promised as regards marrying Zaynab he fulfilled). And verily Fāṭimah, the daughter of Muḥammad, is a part of me and I dislike that she may be put to any trial, and by Allāh, the daughter of the Messenger of Allāh and the daughter of the enemy of Allāh will never be joined together [in marriage] to one man.” Thereupon ʿAlī abandoned the marriage proposal.¹ The scholars have mentioned several reasons, which, taken individually or together, explain why the Prophet (PBUH) did not allow ʿAlī to proceed with this marriage. First, the Prophet (PBUH) objected to uniting the daughter of the Messenger of Allāh (PBUH) and the daughter of the enemy of Allāh as co-wives under one man. Moreover, such a marriage would have caused Fāṭimah distress, and whatever harms her would harm the Prophet (PBUH), and harming the Prophet (PBUH) is a major sin. Thus, he (PBUH) forbade ʿAlī from doing this out of compassion for him, for anyone who causes him harm will be doomed. Additionally, this incident occurred after the conquest of Makkah, at a time when Fāṭimah had lost her mother and subsequently her sisters, leaving her without anyone to comfort her if she became jealous, and allowing her reason for jealousy would have intensified her grief. Furthermore, the Prophet (PBUH) prohibited ʿAlī’s marriage out of care and respect for Fāṭimah, because she held a place of love and esteem in his heart that was second only to his wife Khadījah. It is important to note that this consideration applied only to Fāṭimah [may Allāh be pleased with her] and Khadījah [may Allāh be pleased with her], as they were perfect women. The Prophet (PBUH) said that throughout the history of the world, only four women could attain the high standards of true perfection established by Islam: “Sufficient for you among the women of mankind are Maryam bint ʿImrān, Khadījah bint Khuwaylid, Fāṭimah bint Muḥammad, and ʾĀsiyah, the wife of Pharaoh.”² These four women are the only perfect women in all of humanity. Among them, the last two belong to the same household—Khadījah, the mother, and Fāṭimah, her daughter. It has been reported that Fāṭimah [may Allāh be pleased with her] was the most perfect woman to have ever lived.³ Khadījah was one of the greatest women in the world. She held immense value in the eyes of the Prophet (PBUH) to the extent that he did not marry another woman while she was alive—for twenty-four years and six months. Khadījah [may Allāh be pleased with her] was highly conscientious in her duties as a wife. She possessed rare intelligence and skill, which made the household of her husband (PBUH) a heaven on earth. Thus, he (PBUH) had no need for any other woman. It is important to note that the Prophet (PBUH)’s objection to ʿAlī’s marriage does not in any way support attempts to restrict polygamy. The Prophet (PBUH) addressed this directly in the same story, stating: “…And I am not making unlawful that which is lawful, nor making lawful that which is unlawful.”⁴