Habib bin Abi Thabit says that once I came to Abu Wa'il in the mosque of his house so that I could ask him about those people whom Sayyiduna Ali killed at Nahrawan—what command of Sayyiduna Ali did they accept, and in what did they differ? And on what basis did Sayyiduna Ali consider fighting them permissible? He said: We were at Siffin, and when the number of the slain from the people of Syria increased, they climbed up a mound. Sayyiduna Amr bin Al-As said to Sayyiduna Amir Muawiyah: Send a copy of the Noble Qur'an to Sayyiduna Ali and invite him to the Book of Allah; he will not refuse your proposal in any way. Accordingly, a man came to Sayyiduna Ali with this message and said: The Book of Allah is the arbiter between us and you. And he recited this verse: "Have you not seen those who were given a portion of the Book? They are invited to the Book of Allah so that it may judge between them..." The Book of Allah is the arbiter between us and you. After this, the Khawarij, whom we used to call Qurra at that time, came to Sayyiduna Ali with their swords hanging on their shoulders and said: O Commander of the Faithful, what are we waiting for regarding these people who are on the mound? Should we not attack them with our swords until Allah decides between us and them? At this, Sayyiduna Sahl bin Hunaif spoke and said: O people, do not always consider yourselves to be right. We have also seen the day of Hudaybiyyah, in which there was a peace treaty between the Prophet (peace be upon him) and the polytheists. If we had wanted to fight, we could have done so. During this, Sayyiduna Umar presented himself in the court of the Messenger (peace be upon him) and said: O Messenger of Allah! Are we not upon the truth and are they not upon falsehood? Will not our slain go to Paradise and their slain to Hell? The Prophet (peace be upon him) said: Why not? He said: Then why should we accept humiliation in our religion and make peace, and return in such a way that Allah has not yet decided between us and them? The Prophet (peace be upon him) said: O Ibn Khattab, I am the Messenger of Allah; He will never forsake me. Sayyiduna Umar returned in anger and could not be patient. He went to Sayyiduna Abu Bakr and the same questions and answers took place. Sayyiduna Siddiq Akbar said: He is the Messenger of Allah, and Allah will never forsake him. After this, Surah Al-Fath was revealed, so the Prophet (peace be upon him) sent me to Sayyiduna Umar and recited this Surah to him. Sayyiduna Umar said: O Messenger of Allah! Is this a victory? The Prophet (peace be upon him) said: Yes.