Sahih al-Bukhari 4270
Sahih al-Bukhari · Book 64: Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi) · The dispatch of Usama bin Zaid to Al-Huraqat
Narrated Salama bin Al-Akwa`:
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ ، حَدَّثَنَا حَاتِمٌ ، عَنْ يَزِيدَ بْنِ أَبِي عُبَيْدٍ ، قَالَ سَمِعْتُ سَلَمَةَ بْنَ الأَكْوَعِ ، يَقُولُ غَزَوْتُ مَعَ النَّبِيِّ صلى الله عليه وسلم سَبْعَ غَزَوَاتٍ، وَخَرَجْتُ فِيمَا يَبْعَثُ مِنَ الْبُعُوثِ تِسْعَ غَزَوَاتٍ، مَرَّةً عَلَيْنَا أَبُو بَكْرٍ، وَمَرَّةً عَلَيْنَا أُسَامَةُ.
I fought in seven Ghazwat (i.e. battles) along with the Prophet (ﷺ) and fought in nine battles, fought by armies dispatched by the Prophet. Once Abu Bakr was our commander and at another time, Usama was our commander.