It is narrated from Habib bin Abi Thabit, who says: I was present with Sayyiduna Abu Wa’il in his mosque. I wanted to ask him about those people whom Sayyiduna Ali (may Allah be pleased with him) killed at Nahrawan—how did people accept his word, and how did those who did not accept, refuse him, and how did Sayyiduna Ali (may Allah be pleased with him) consider it lawful to kill them? He replied: We were present at Siffin, and when fierce fighting broke out with the people of Syria, they took refuge on a mound. Sayyiduna Amr bin al-As (may Allah be pleased with him) said to Sayyiduna Mu’awiyah (may Allah be pleased with him): Send the Mushaf to Ali (may Allah be pleased with him) and invite him to come to the judgment of the Book of Allah; he will not refuse to accept this. So a man came to Sayyiduna Ali (may Allah be pleased with him) with the Qur’an and said:“The Book of Allah is sufficient between us and you. The statement of Allah, the Exalted, is: {اَلَمْ تَرَ اِلَی الَّذِیْنَ اُوْتُوْا نَصِیْبًا مِّنَ الْکِتٰبِ یُدْعَوْنَ اِلٰی کِتٰبِ اللّٰہِ لِیَحْکُمَ بَیْنَھُمْ ثُمَّ یَتَوَلّٰی فَرِیْقٌ مِّنْھُمْ وَھُمْ مُّعْرِضُوْنَ} … Have you not seen those who were given a portion of the Book of Allah? They are invited to the Book of Allah so that it may judge between them, but then a party of them turn away in aversion.”Hearing this, Sayyiduna Ali (may Allah be pleased with him) said:“Alright, I am more deserving of this; the Book of Allah will judge between us and you.”The Kharijites, whom we used to call Qurra’ in those days, came to Sayyiduna Ali (may Allah be pleased with him) with their swords hanging on their shoulders. They said:“O Commander of the Faithful! These people who have taken refuge on the mound, why are we waiting for them? Why do we not draw our swords and go out to fight them until Allah decides between us and them?”Hearing this, Sayyiduna Sahl bin Hunaif (may Allah be pleased with him) spoke and said:“People! Reconsider your opinion or statement. I saw that on the day of the Treaty of Hudaybiyyah, when peace was made between the Messenger of Allah (peace and blessings be upon him) and the polytheists, if we had wanted to fight that day, we could have fought. When the matter of peace was discussed, Sayyiduna Umar (may Allah be pleased with him) came to the Messenger of Allah (peace and blessings be upon him) and said: ‘O Messenger of Allah! Are we not upon the truth and are they not upon falsehood? Are our slain in Paradise and their slain in Hell?’ The Prophet (peace and blessings be upon him) said: ‘Yes.’ Sayyiduna Umar (may Allah be pleased with him) said: ‘Then why should we show weakness in our religion? And why should we return when Allah has not yet decided between us and them?’ The Prophet (peace and blessings be upon him) said: ‘O Ibn Khattab! I am the Messenger of Allah, and Allah will never forsake me.’ Hearing this, Sayyiduna Umar (may Allah be pleased with him) returned in anger. Unable to be patient, he went to Sayyiduna Abu Bakr (may Allah be pleased with him) and said: ‘O Abu Bakr! Are we not upon the truth and are they not upon disbelief? Are our slain in Paradise and their slain in Hell?’ Sayyiduna Abu Bakr (may Allah be pleased with him) said: ‘Yes, indeed.’ So Sayyiduna Umar (may Allah be pleased with him) said: ‘Then why should we show such weakness in our religion? And why should we return like this when Allah has not yet decided between us and them?’ Sayyiduna Abu Bakr (may Allah be pleased with him) said: ‘O Ibn Khattab! He is the Messenger of Allah, and Allah will never forsake him.’ Sayyiduna Sahl (may Allah be pleased with him) says: After this, Surah al-Fath was revealed. The Messenger of Allah (peace and blessings be upon him) sent me to Sayyiduna Umar (may Allah be pleased with him) to recite it to him. Sayyiduna Umar (may Allah be pleased with him) said: ‘O Messenger of Allah! Will the outcome of this treaty be victory?’ The Prophet (peace and blessings be upon him) said: ‘Yes.’