Abu Hurayrah (may Allah be pleased with him) reported that a Bedouin man came to the Messenger of Allah (may Allah's peace and blessings be upon him) and said: "My wife has given birth to a black boy." The Prophet asked him: "Do you have camels?" He replied: 'Yes.' The Prophet asked: "What color are they?" He replied: 'Red.' The Prophet asked: "Is any of them gray?" He replied: 'Yes.' The Prophet asked: "From where did that grayness come?" He said: "It might have inherited it from its ancestors." The Prophet (may Allah's peace and blessings be upon him) said: "Perhaps this son of yours (also) inherited it (this color) from his ancestors."
عن أبي هريرة -رضي الله عنه- أن رسول الله صلى الله عليه وسلم جاءه أعرابي فقال: يا رسول الله، إن امرأتي ولدت غلاما أسود، فقال: «هل لك من إبل» قال: نعم، قال: «ما ألوانها» قال: حمر، قال: «هل فيها من أَوْرَقَ» قال: نعم، قال: «فأنى كان ذلك» قال: أراه عرق نزعه، قال: «فلعل ابنك هذا نَزَعَهُ عِرْقٌ»
شرح الحديث :
A boy was born to a man from the tribe of Fazārah, and the color of the baby's skin was different from that of his father and mother. The father thus had doubts that the boy was not his child, so he went to the Prophet (may Allah's peace and blessings be upon him) to inform him that his wife gave birth to a black child, thus implying an accusation of adultery. The Prophet understood what he meant and wanted to convince the man and remove his doubt, so he made an analogy which is familiar and known to the man. He asked him if he had camels and what their color was. He replied in the affirmative and that they were red. He then asked him if there were any grey camels among them, and he said: 'Yes.' The Prophet then asked him where that different color came from. The man replied that perhaps it came by heredity from the lineage of the animal; one of its parentages. The Prophet (may Allah's peace and blessings be upon him) said that the case of his son was similar to this and that there might have been a black person in the man's ancestors, so therefore the boy inherited the color. The man was convinced with this sound analogy, and the doubts in his mind were removed.