Sahih al-Bukhari 4087
Sahih al-Bukhari · Book 64: Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi) · The Ghazwa of Ar-Raji’, Ri’l, Dhakwan and Bi’r Ma’una and the narration about Khubaib and his companions
Narrated Jabir:
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ ، حَدَّثَنَا سُفْيَانُ ، عَنْ عَمْرٍو ، سَمِعَ جَابِرًا ، يَقُولُ الَّذِي قَتَلَ خُبَيْبًا هُوَ أَبُو سِرْوَعَةَ.
The person who killed Khubaib was Abu Sarua (i.e. `Uqba bin Al-Harith).