Musannaf Ibn Abi Shayba 9:1137

Abu Mu'awiyah narrated to us, from al-A'mash, from Sa'd ibn 'Ubaydah, from Abu 'Abd al-Rahman, from 'Ali, who said: I said, "O Messenger of Allah, why do you yearn for [marriage among] Quraysh and leave us?" He said, "Do you have anything?" I said, "Yes, the daughter of Hamzah." The Messenger of Allah (peace and blessings of Allah be upon him) said, "She is not lawful for me; she is the daughter of my brother through breastfeeding."