Abu Hurairah reported,

The Messenger of Allah ﷺ said, "Every child is born upon the natural disposition, then his parents make him a Jew or a Christian, just as camels are born whole from the mother camel. Do you find any with cropped ears among them?"They asked, "Messenger of Allah, what do you think about one who dies while still a child?"He replied, "Allah knows best what they would have done."In another narration, "Every child is born upon this natural disposition, then his parents make him a Jew or a Christian, just as you breed camels. Do you find any with cropped ears among them, until you yourselves crop them?"In yet another narration, "Every human being is born by his mother upon the natural disposition. Then his parents make him a Jew, a Christian, or a Magian. If both parents are Muslims, then he is a Muslim. Every human being whom his mother bears is poked by Satan in his sides, except for Maryam and her son."

عن أبي هريرة

أن رسول الله ﷺ قال: كل مولود يولد على الفطرة، فأبواه يهودانه أو ينصرانه كما تناتج الإبل من بهيمة جمعاء، هل تحس فيها من جدعاء؟ قالوا: يا رسول الله! أرأيت الذي يموت وهو صغير؟ قال: الله أعلم بما كانوا عاملين. وفي رواية: من يولد يولد على هذه الفطرة، فأبواه يهودانه وينصرانه كما تنتجون الإبل، فهل تجدون فيها جدعاء؟ حتى تكونوا أنتم تجدعونها. وفي رواية أخرى: كل إنسان تلده أمه على الفطرة، وأبواه بعد يهودانه، وينصرانه ويمجسانه، فإن كانا مسلمين فمسلم، كل إنسان تلده أمه يلكزه الشيطان في حضنيه، إلا مريم وابنها.