صَحِيحُ مُسْلِمٍ
Sahih Muslim 1447 a
The Book of Suckling
The daughter of one's brother through breastfeeding is forbidden in marriage
وَحَدَّثَنَا هَدَّابُ بْنُ خَالِدٍ، حَدَّثَنَا هَمَّامٌ، حَدَّثَنَا قَتَادَةُ، عَنْ جَابِرِ بْنِ زَيْدٍ، عَنِ ابْنِ، عَبَّاسٍ أَنَّ النَّبِيَّ صلى الله عليه وسلم أُرِيدَ عَلَى ابْنَةِ حَمْزَةَ فَقَالَ إِنَّهَا لاَ تَحِلُّ لِي إِنَّهَا ابْنَةُ أَخِي مِنَ الرَّضَاعَةِ وَيَحْرُمُ مِنَ الرَّضَاعَةِ مَا يَحْرُمُ مِنَ الرَّحِمِ .
Ibn Abbas (Allah be pleased with them) reported: It was proposed that he (the Prophet) be married to the daughter of Hamza, whereupon he said: She is not lawful for me for she is the daughter of my foster-brother, and that is unlawful by reason of fosterage what is unlawful by reason of genealogy.
Sahih Muslim, 1447 aSahihصحيح