(3) باب تَحْرِيمِ ابْنَةِ الأَخِ مِنَ الرَّضَاعَةِ
'Ali (Allah be pleased with him) reported having said this:
Messenger of Allah, why is it that you select (your wife) from among the Quraish, but you ignore us (the nearest of the kin)? Thereupon he said: Have you anything for me (a suitable match for me)? I said; Yes, the daughter of Hamza, whereupon Allah's Messenger (ﷺ) said: She is not lawful for me, for she is the daughter of my brother by reason of fosterage.
Reference: Sahih Muslim 1446 a
In-book reference: Book 17, Hadith 14
USC-MSA web (English) reference(deprecated numbering scheme): Book 8, Hadith 3407