Overall meaning:
ʿAlī b. Abī Ṭālib (may Allah be pleased with him) asked the Prophet ﷺ for permission to marry the daughter of their paternal uncle Ḥamzah.¹
The Prophet ﷺ told him that she was not lawful for him, because she was the daughter of his milk-brother.
For both the Prophet ﷺ and his uncle Ḥamzah had been nursed by Thuwaybah, the freedwoman of Abū Lahab; thus Ḥamzah became his brother through suckling, making his daughter the Prophet’s niece. Whatever marriage prohibitions arise from lineage likewise arise from suckling.
Points derived from the ḥadith
- Suckling establishes a relationship of maḥram status, including the prohibition of marriage.
- The rulings it produces mirror those produced by blood-kinship: every woman forbidden through ancestry is equally forbidden through the corresponding relationship created by suckling.
- The prohibition spreads, because of suckling, only to the nursling himself and his descendants—his sons, daughters, and their progeny. It does not extend to his ascendants (father, mother, and forefathers) nor to his collateral relatives (brothers, sisters, paternal or maternal uncles and aunts). None of these fall under the ruling.
The nursling is treated as one of the wet-nurse’s own children: she is his mother, the one whose milk it is becomes his father, their children are his brothers and sisters, and their forefathers—no matter how far removed—are his grandparents; likewise, their paternal and maternal uncles and aunts are his own.
Third Ḥadith
ʿĀʾishah (may Allah be pleased with her) said: “After the verse of veiling had been revealed, Aflah—the brother of Abū al-Quʿays—sought permission to enter upon me. I said, ‘By Allah, I will not allow him in until I ask the Messenger of Allah ﷺ, for the brother of Abū al-Quʿays is not the one who nursed me; it was the wife of Abū al-Quʿays who nursed me.’
“So I went to the Messenger of Allah ﷺ and said, ‘O Messenger of Allah, the man himself did not nurse me; rather, his wife did.’
“He said, ‘Let him in, for he is your uncle. May your right hand be covered in dust!’
ʿUrwah said: Because of this ʿĀʾishah used to say, ‘Make unlawful through suckling whatever is unlawful through lineage.’