Narrated Abu Hurairah (RA): A man said, "O Allah's Messenger, my wife has given birth to a black son." He asked, "Have you any camels?" He replied, "Yes." He asked, "What is their color?" He replied, "They are red." He asked, "Is there a dusky (dark) one among them?" He replied, "Yes." He asked, "How has that come about?" He replied, "It is perhaps a strain to which it has reverted (i.e. heredity)." He said, "It is perhaps a strain to which this son of yours has reverted." [Agreed upon].