Sahih Bukhari Volume 7, Book 68, Hadith 5307

حَدَّثَنَا يَحْيَى بْنُ قَزَعَةَ، حَدَّثَنَا مَالِكٌ، عَنِ ابْنِ شِهَابٍ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَجُلاً، أَتَى النَّبِيَّ صلى الله عليه وسلم فَقَالَ يَا رَسُولَ اللَّهِ وُلِدَ لِي غُلاَمٌ أَسْوَدُ‏.‏ فَقَالَ ‏"‏ هَلْ لَكَ مِنْ إِبِلٍ ‏"‏‏.‏ قَالَ نَعَمْ‏.‏ قَالَ ‏"‏ مَا أَلْوَانُهَا ‏"‏‏.‏ قَالَ حُمْرٌ‏.‏ قَالَ ‏"‏ هَلْ فِيهَا مِنْ أَوْرَقَ ‏"‏‏.‏ قَالَ نَعَمْ‏.‏ قَالَ ‏"‏ فَأَنَّى ذَلِكَ ‏"‏‏.‏ قَالَ لَعَلَّهُ نَزَعَهُ عِرْقٌ‏.‏ قَالَ ‏"‏ فَلَعَلَّ ابْنَكَ هَذَا نَزَعَهُ ‏"‏‏

Narrated By Abu Huraira : A man came to the Prophet and said, "O Allah's Apostle! A black child has been born for me." The Prophet asked him, "Have you got camels?" The man said, "Yes." The Prophet asked him, "What colour are they?" The man replied, "Red." The Prophet said, "Is there a grey one among them?' The man replied, "Yes." The Prophet said, "Whence comes that?" He said, "May be it is because of heredity." The Prophet said, "May be your latest son has this colour because of heredity."