Sahih al-Bukhari 1384

It was related that Abu Hurayra said, "The Prophet, may Allah bless him and grant him peace, was asked about the children of the idolaters and he said, 'Since Allah created them He knows best what they would have done.'" 1319 It is related that Abu Hurayra that the Prophet, may Allah bless him and grant him peace, said, "Every child is born in a natural state and his parents make him a Jew, Christian or Magian just as the animal gives birth to an animal - do you see any mutilation in it?"