Musannaf Ibn Abi Shayba 9:401

Ibn Fudayl narrated to us, from Jamil, from Abdullah ibn Ka’b or Ka’b ibn Abdullah, who said: The Messenger of Allah (may Allah bless him and grant him peace) married a woman from Ghifar. He sat with her in the position of a man with a woman, and he saw a patch of vitiligo on her flank. He stood up from her and said: "Adjust your clothes upon yourself and return to your house."