It was narrated from Ibn 'Umar that:
a man frorn the desert people came to the Prophet and said: "O Messenger of Allah, my wife has given birth on my bed to a black boy, and there are no black people among my family." He said: "Do you have camels?" He said: "Yes." He said: "What color are they?" He said: "Red." He said: are there any black ones among them?" He said, "No." He said: "Are there any grey ones among them?" He said- "Yes." He said "How is that?" He said: "Perhaps it is hereditary." He said: "Perhaps (the color of) this son of yours is also hereditary."

حَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا عَبَاءَةُ بْنُ كُلَيْبٍ اللَّيْثِيُّ أَبُو غَسَّانَ، عَنْ جُوَيْرِيَةَ بْنِ أَسْمَاءَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، . أَنَّ رَجُلاً، مِنْ أَهْلِ الْبَادِيَةِ أَتَى النَّبِيَّ ـ ﷺ ـ فَقَالَ يَا رَسُولَ اللَّهِ إِنَّ امْرَأَتِي وَلَدَتْ عَلَى فِرَاشِي غُلاَمًا أَسْوَدَ وَإِنَّا أَهْلُ بَيْتٍ لَمْ يَكُنْ فِينَا أَسْوَدُ قَطُّ . قَالَ " هَلْ لَكَ مِنَ إِبِلٍ " . قَالَ نَعَمْ . قَالَ " فَمَا أَلْوَانُهَا " . قَالَ حُمْرٌ . قَالَ " هَلْ فِيهَا أَسْوَدُ " . قَالَ لاَ . قَالَ " فَهَلْ فِيهَا أَوْرَقُ " . قَالَ نَعَمْ . قَالَ " فَأَنَّى كَانَ ذَلِكَ " . قَالَ عَسَى أَنْ يَكُونَ نَزَعَهُ عِرْقٌ . قَالَ " فَلَعَلَّ ابْنَكَ هَذَا نَزَعَهُ عِرْقٌ " .