Mishkat al-Masabih 111

ʿĀʾisha reported: I asked, ‘Messenger of God, what of the children of believers?’ He replied, ‘They are with their fathers.’ I asked, ‘Without having done deeds?’ He said, ‘God knows best what they would have done.’ I asked, ‘And what of the children of polytheists?’ He replied, ‘They are with their fathers.’ I asked, ‘Without having done deeds?’ He said, ‘God knows best what they would have done.’ Abu Dawud transmitted it.