كتاب الرضاع
17  
The Book of Suckling
(3)
Chapter: The daughter of one's brother through breastfeeding is forbidden in marriage
(3)
باب تَحْرِيمِ ابْنَةِ الأَخِ مِنَ الرَّضَاعَةِ ‏
Sahih Muslim 1447 a

Ibn Abbas (Allah be pleased with them) reported:

It was proposed that he (the Holy 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.
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 ‏"‏ ‏.‏
Reference : Sahih Muslim 1447a
In-book reference : Book 17, Hadith 16
USC-MSA web (English) reference : Book 8, Hadith 3409
  (deprecated numbering scheme)