Mustadrak al-Hakim — Hadith 4648

It is narrated from Hamzah bin Abdullah bin Umar that he was sitting with his father, Abdullah bin Umar (may Allah be pleased with him), when a man from Iraq came and said: O Abu Abd al-Rahman! By Allah, I have tried my utmost to adopt your way, to follow you in the matter of the people's division, and to stay away from evil as much as I can. But I read a decisive verse of the Book of Allah that has gripped my heart, so tell me about it. What is your view concerning this statement of Allah, the Mighty and Majestic: "And if two groups of the believers fight one another, then make peace between them. Then if one of them transgresses against the other, fight the one that transgresses until it returns to the command of Allah. Then if it returns, make peace between them with justice and be equitable. Indeed, Allah loves those who are equitable" [Surah al-Hujurat: 9]? Abdullah bin Umar (may Allah be pleased with him) said: What business is that of yours? Go away from me. When the man had left and disappeared from sight, Abdullah bin Umar (may Allah be pleased with them both) turned to us and said: "I have not felt as much regret or distress in my heart over any matter as I feel over the fact that I did not fight this transgressing group (al-fi'ah al-baghiyah) as Allah, the Mighty and Majestic, commanded me."
This is a vast chapter which a group of the senior Tabi'un narrated from Abdullah bin Umar. I placed first the narration of Shu'ayb bin Abi Hamzah from al-Zuhri and confined myself to it because it is sahih (authentic) on the condition of Imam Bukhari and Imam Muslim. And as for what has been mentioned of Usamah bin Zayd refraining from fighting (the reality of it is as follows):