The Messenger of Allah ﷺ was urged to marry the daughter of Hamza bin Abdul-Muttalib. He said, "She is the daughter of my brother through breastfeeding, and breastfeeding makes unlawful what lineage makes unlawful."
حدثنا حميد بن مسعدة وأبو بكر بن خلاد قالا حدثنا خالد بن الحارث حدثنا سعيد عن قتادة عن جابر بن زيد
أن رسول الله ﷺ أريد على بنت حمزة بن عبد المطلب فقال إنها ابنة أخي من الرضاعة وإنه يحرم من الرضاعة ما يحرم من النسب
Bukhari recorded it in "Testimonies," in the chapter on testimony regarding lineage, well-known nursing relationships, and death from long ago, no. 2645, 5100, and Muslim recorded it in "Nursing," in the chapter on the prohibition of a niece through nursing, no. 1447, from the hadith of Qatada, with this same account.