Nahj al-Balāgha
Hadith 171ومن كلام له (عليه السلام) يجري مجرى الخطبة [وفيه يذكر فضائله (عليه السلام) قاله بعد وقعة النهروان]
Amīr al-mu’minīn’s utterance which runs like a Sermon about his own steadfastness in religion and precedence in (acceptance of) belief. Spoken after the Battle of Nahrawān