Sahih al-Bukhari 4169
Book 64: Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi) · Narrated by Yazid bin Abi Ubaid
Arabic
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا حَاتِمٌ، عَنْ يَزِيدَ بْنِ أَبِي عُبَيْدٍ، قَالَ قُلْتُ لِسَلَمَةَ بْنِ الأَكْوَعِ عَلَى أَىِّ شَىْءٍ بَايَعْتُمْ رَسُولَ اللَّهِ صلى الله عليه وسلم يَوْمَ الْحُدَيْبِيَةِ. قَالَ عَلَى الْمَوْتِ.
English translation
Narrated Yazid bin Abi Ubaid:I said to Salama bin Al-Akwa`, "For what did you give the Pledge of allegiance to Allah's Messenger (ﷺ) on the day of Al-Hudaibiya?" He replied, "For death (in the Cause of Islam)
Reference: Sahih al-Bukhari 4169, Book of Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi). English translation by Dr. Muhammad Muhsin Khan.