It is narrated from Sayyiduna Ali (may Allah be pleased with him); he said: I said: "O Messenger of Allah! Why is it that I see you inclined towards Quraysh while you leave us?" He (peace and blessings be upon him) said: "Do you have someone in mind?" I said: "Yes, the daughter of Hamzah." He (peace and blessings be upon him) said: "She is the daughter of my foster brother."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 2908