Hadithcore
Sahih al-Bukhari, 4273
sahih

Narrated Yazid bin Abi Ubaid:

Salama bin Al-Akwa` said, "I fought in seven Ghazwat along with the Prophet." He then mentioned Khaibar, Al-Hudaibiya, the day (i.e. battle) of Hunain and the day of Al-Qurad. I forgot the names of the other Ghazwat.

حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ، حَدَّثَنَا حَمَّادُ بْنُ مَسْعَدَةَ، عَنْ يَزِيدَ بْنِ أَبِي عُبَيْدٍ، عَنْ سَلَمَةَ بْنِ الأَكْوَعِ، قَالَ غَزَوْتُ مَعَ النَّبِيِّ صلى الله عليه وسلم سَبْعَ غَزَوَاتٍ‏.‏ فَذَكَرَ خَيْبَرَ وَالْحُدَيْبِيَةَ وَيَوْمَ حُنَيْنٍ وَيَوْمَ الْقَرَدِ‏.‏ قَالَ يَزِيدُ وَنَسِيتُ بَقِيَّتَهُمْ‏.‏

References2 variants
In-Book Reference
Book 64, Hadith 307
USC-MSA web (English) reference
Vol. 5, Book 59, Hadith 571 (deprecated numbering scheme)