983 – Ibn ʿAbbās (may Allah be pleased with him) related that the Prophet ﷺ was offered the hand of Ḥamzah’s daughter in marriage, whereupon he said, “She is not lawful for me; she is my brother’s daughter through nursing, and whatever is forbidden through nursing is forbidden through lineage.” Agreed upon. (1)

Vocabulary of the ḥadīth
• “She is my brother’s daughter through nursing” – the reason why marriage to her is prohibited.
• “Whatever is forbidden through nursing is forbidden through lineage.” Al-Khattābī said, “The wording is general while its meaning is specific. In detail: the general effect of nursing is that the wet-nurse and her blood relatives become prohibited to the nursling just as if they were bound by lineage, but this ruling does not apply in the same way to the nursling and his relatives.”

Lessons drawn from the ḥadīth
1 – The Prophet ﷺ never married a woman from Banū Hāshim. He was offered the daughter of his uncle Ḥamzah ibn ʿAbd al-Muṭṭalib, who left no other child besides her.
2 – Paternal cousins are lawful for him and for the rest of his community, as the Most High says: “O Prophet, We have made lawful to you your wives to whom you have given their bridal-gifts, those whom your right hand possesses of what Allah has granted you, your paternal cousins, your paternal aunts’ daughters, your maternal cousins, and your maternal aunts’ daughters who migrated with you” (al-Aḥzāb 33:50).
3 – The Messenger ﷺ explained the impediment to marrying Ḥamzah’s daughter: he and Ḥamzah were brothers through nursing, which made him her paternal uncle by nursing; whatever is forbidden through nursing is the same as what is forbidden through lineage.
4 – The woman who nursed the Prophet ﷺ and his uncle Ḥamzah was Thuwaibah, the freedwoman of Abū—