Sahih al-Bukhari #3955 · Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)

Sahih al-BukhariAl-Bara
Sahih al-Bukhari · Book 64 · Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Sahih al-Bukhari · كتاب 64 · كتاب المغازي
I and Ibn 'Umar were considered too young to take part in the battle of Badr
حَدَّثَنَا مُسْلِمٌ، حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي إِسْحَاقَ، عَنِ الْبَرَاءِ، قَالَ اسْتُصْغِرْتُ أَنَا وَابْنُ، عُمَرَ‏.‏
Reference : Sahih al-Bukhari 3955In-book reference : Book 64, Hadith 7