Abdullah bin Abbas reported,

The Messenger of Allah ﷺ was asked about the children of the polytheists. He replied, "Allah knows best what they would have done had He let them live."

Muslim 6765

Sahih

و حدثنا يحيى بن يحيى أخبرنا أبو عوانة عن أبي بشر عن سعيد بن جبير

عن ابن عباس قال

سئل رسول الله ﷺ عن أطفال المشركين قال الله أعلم بما كانوا عاملين إذ خلقهم

مسلم 6765صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Muslim
Book
Decree
Chapter
Meaning of "every child is born upon fitrah" and the ruling on the death of children of disbelievers and children of Muslims
Numbering
Darussalam 6765
Muslim 6765