Sayyidah Aishah (may Allah be pleased with her) says that Sayyiduna Hassan (may Allah be pleased with him) said: O Messenger of Allah! Give me permission concerning Abu Sufyan. He (peace and blessings be upon him) said: "What then of my kinship with him?" Sayyiduna Hassan (may Allah be pleased with him) said: I will draw you out from among them just as a straw is drawn out of flour. Then he said: "From the family of Banu Hashim is the hump of nobility, and O children of the daughter of Makhzum, your father is a slave."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 21105