Full Sharh — Musnad Ahmad 591
حَدَّثَنَا إِسْمَاعِيلُ، حَدَّثَنَا أَيُّوبُ، عَنْ مُحَمَّدٍ، عَنْ عَبِيدَةَ، عَنْ عَلِيٍّ، رَضِيَ اللَّهُ عَنْهُ قَالَ ذُكِرَ الْخَوَارِجُ فَقَالَ فِيهِمْ مُخْدَجُ الْيَدِ أَوْ مُودَنُ الْيَدِ أَوْ مُثَدَّنُ الْيَدِ لَوْلَا أَنْ تَبْطَرُوا لَحَدَّثْتُكُمْ بِمَا وَعَدَ اللَّهُ الَّذِينَ يَقْتُلُونَهُمْ عَلَى لِسَانِ مُحَمَّدٍ قُلْتُ أَنْتَ سَمِعْتَهُ مِنْ مُحَمَّدٍ قَالَ إِي وَرَبِّ الْكَعْبَةِ إِي وَرَبِّ الْكَعْبَةِ إِي وَرَبِّ الْكَعْبَةِ.
English Translation
It was narrated from `Abeedah that ‘Ali (رضي الله عنه) mentioned the Khawarij and said:: Among them is a man with a defective arm, or an incomplete arm, or a small arm. If you could exercise restraint, I would have told you what Allah promised on the lips of Muhammad (ﷺ) to those who kill them. I said: Did you hear that from Muhammad (ﷺ)? He said: Yes, by the Lord of the Ka`bah; yes, by the Lord of the Ka`bah; yes, by the Lord of the Ka`bah.
Source
Musnad Ahmad(مسند أحمد)
Musnad 'Ali Ibn Abi Talib
Hadith Number
591