Sahih al-Bukhari 1359
Sahih al-Bukhari · Book 23: Funerals (Al-Janaa'iz) · If a boy becomes a Muslim and then dies, should a funeral prayer be offered for him? Should Islam be explained to a boy?
Narrated Abu Huraira:
حَدَّثَنَا عَبْدَانُ ، أَخْبَرَنَا عَبْدُ اللَّهِ ، أَخْبَرَنَا يُونُسُ ، عَنِ الزُّهْرِيِّ ، أَخْبَرَنِي أَبُو سَلَمَةَ بْنُ عَبْدِ الرَّحْمَنِ ، أَنَّ أَبَا هُرَيْرَةَ ـ رضى الله عنه ـ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَا مِنْ مَوْلُودٍ إِلاَّ يُولَدُ عَلَى الْفِطْرَةِ، فَأَبَوَاهُ يُهَوِّدَانِهِ أَوْ يُنَصِّرَانِهِ أَوْ يُمَجِّسَانِهِ، كَمَا تُنْتَجُ الْبَهِيمَةُ بَهِيمَةً جَمْعَاءَ، هَلْ تُحِسُّونَ فِيهَا مِنْ جَدْعَاءَ " . ثُمَّ يَقُولُ أَبُو هُرَيْرَةَ ـ رضى الله عنه {فِطْرَةَ اللَّهِ الَّتِي فَطَرَ النَّاسَ عَلَيْهَا لاَ تَبْدِيلَ لِخَلْقِ اللَّهِ ذَلِكَ الدِّينُ الْقَيِّمُ}
Allah's Messenger (ﷺ) said, "Every child is born with a true faith of Islam (i.e. to worship none but Allah Alone) but his parents convert him to Judaism, Christianity or Magainism, as an animal delivers a perfect baby animal. Do you find it mutilated?" Then Abu Huraira recited the holy verses: "The pure Allah's Islamic nature (true faith of Islam) (i.e. worshipping none but Allah) with which He has created human beings. No change let there be in the religion of Allah (i.e. joining none in worship with Allah). That is the straight religion (Islam) but most of men know, not." (30.30)