سنن أبي داود

Abu Hurairah said A man from Banu Fazarah came to the Prophet (ﷺ) and said “My wife has given birth to a black son”. He said “Have you any camels?” He said “They are red”. He asked “Is there a dusky one among them?” He replied “Some of them are dusky”. He asked “How do you think they have come about?” He replied “This may be a strain to which they reverted”. He said “And this is perhaps a strain to which the child has reverted.”