Mishkat al-Masabih #84

Abu Huraira reported God’s messenger as saying, “Everyone is born a Muslim, but his parents make him a Jew, a Christian, or a Magian; just as a beast is born whole. Do you find some among them maimed?” Then he was saying, “God’s pattern on which He formed mankind. There is no alteration of God’s creation. That is the true religion.” 1 (Bukhari and Muslim.) 1 Quran, xxx, 30. It is not quite clear whether these words were recited by the Prophet or by Abu Huraira.