(6) بَاب مَعْنَى كُلِّ مَوْلُودٍ يُولَدُ عَلَى الْفِطْرَةِ وَحُكْمِ مَوْتِ أَطْفَالِ الْكُفَّارِ وَأَطْفَالِ الْمُسْلِمِينَ
Abu Huraira reported Allah's Messenger (ﷺ) as saying:
The mother of every person gives him birth according to his true nature. It is subsequently his parents who make him a Jew or a Christian or a Magian. Had his parents been Muslim he would have also remained a Muslim. Every person to whom his mother gives birth (has two aspects of his life) ; when his mother gives birth Satan strikes him but it was not the case with Mary and her son (Jesus Christ).
Reference: Sahih Muslim 2659 a
In-book reference: Book 46, Hadith 40
USC-MSA web (English) reference(deprecated numbering scheme): Book 33, Hadith 6429