Musnad Ahmad 778:2

Sufyan narrated to us, from Isma'il bin Umayyah, from Ibn Abi Mulaykah, from 'Uqbah bin al-Harith, who said: I married the daughter of Abu Ihab. Then a black woman came and mentioned that she had suckled us [both]. I came to the Messenger of Allah (peace and blessings of Allah be upon him) and stood before him and spoke to him, but he turned away from me. I stood to his right, and he turned away from me. I said: "O Messenger of Allah, she is only a black woman." He said: "And how [can you keep her] when it has been said?"