Hadith 4159
Chapter 8: Pledging For Death - كتاب البيعة
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا حَاتِمُ بْنُ إِسْمَاعِيلَ، عَنْ يَزِيدَ بْنِ أَبِي عُبَيْدٍ، قَالَ قُلْتُ لِسَلَمَةَ بْنِ الأَكْوَعِ عَلَى أَىِّ شَىْءٍ بَايَعْتُمُ النَّبِيَّ صلى الله عليه وسلم يَوْمَ الْحُدَيْبِيَةِ قَالَ عَلَى الْمَوْتِ .
It was narrated that Yazid bin Abi 'Ubaid said:
"I said to Salamah bin Al-Akwa': 'What pledge did you make to the Prophet on the Day of Al-Hudaibiyyah?' He said: 'For death."'
Reference : Sunan an-Nasa'i 4159
In-book reference : Book 39, Hadith 11