Sahih Muslim Book 33, Hadith Number 6430.

Chapter : Everyone is born according to his true nature and the command pertaining to the demise of the children of the infidels and of the children of the Muslims.

Abu Huraira reported that Allah’s Messenger (may peace be upon him) was asked about the children of the polytheists, whereupon he said: It is Allah Who knows best what they would be doing.