Sahih Muslim Book - 46, Hadith - 6761

حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ ، حَدَّثَنَا عَبْدُ الْعَزِيزِ يَعْنِي الدَّرَاوَرْدِيَّ ، عَنِ الْعَلاَءِ ، عَنْ أَبِيهِ ، عَنْ أَبِي هُرَيْرَةَ ، أَنَّ رَسُولَ اللهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ، قَالَ: كُلُّ إِنْسَانٍ تَلِدُهُ أُمُّهُ عَلَى الْفِطْرَةِ ، وَأَبَوَاهُ بَعْدُ يُهَوِّدَانِهِ وَيُنَصِّرَانِهِ وَيُمَجِّسَانِهِ ، فَإِنْ كَانَا مُسْلِمَيْنِ ، فَمُسْلِمٌ كُلُّ إِنْسَانٍ تَلِدُهُ أُمُّهُ يَلْكُزُهُ الشَّيْطَانُ فِي حِضْنَيْهِ إِلاَّ مَرْيَمَ وَابْنَهَا.

It was narrated from Abu Hurairah that the Messenger of Allah (s.a.w) said: "Every person is borne by his mother in a state of Fitrah, after which his parents make him a Jew or a Christian or a Magian, or if they are Muslims, (they make him) a Muslim. Every person who is borne by his mother is struck on his side by the Shaitan, except for Mariam and her son."