Mishkat al-Masabih #3179

He told of a desert Arab who came to God’s Messenger and said, “My wife has given birth to a black son and I have disowned him.” God’s Messenger asked him whether he had any camels, and when he replied that he had, he asked what their colour was and was told that they were red. He asked if there was a dusky one among them, and was told that there were some. He asked how he thought that had come about, and was told that it was a strain to which they had reverted. Then saying that this was perhaps a strain to which the child had reverted, he did not permit him to disown him. (Bukhari and Muslim.)