Yahya bin Abi Waraqah bin Sa'id (may Allah have mercy on him) said: My mistress, Sayyidah Kabirah bint Sufyan (may Allah be pleased with her), told me (she had lived in the time of Ignorance and was one of the women who gave the pledge of allegiance). She said: I said: "O Messenger of Allah, in the time of Ignorance I buried four of my sons alive?" He (peace and blessings be upon him) said: "Free four necks (slaves)." She said: So I freed your father Sa'id, his two sons Maysarah and Jubayr, and Umm Maysarah. She said: And the Messenger of Allah (peace and blessings be upon him) said to us: "The blood of a whitish (animal) is purer in the sight of Allah than the blood of a black (animal)."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21472