Yahya related to me from Malik from Abu'z Zinad from al-Araj from
Abu Hurayra that the Messenger of Allah, may Allah bless him and grant
him peace, said, "Every child is born on the fitra and it is his
parents who make him a jew or a christian. Just as a camel is born
whole - do you perceive any defect?" They said, "Messenger of Allah,
what happens to people who die when they are (very) young?" He said,
"Allah knows best what they used to do."
Muwatta Malik Book 16, Hadith 54