Mukhtasar Muslim

Narrated from Safwan bin Muharriz that Sayyiduna Jundub bin Abdullah Bajali (may Allah be pleased with him) sent a message to As'as bin Salamah when the turmoil of Sayyiduna Abdullah bin Zubair (may Allah be pleased with him) occurred, saying: Gather some of your brothers so that I may speak to them. As'as sent word to the people, and when they gathered, Sayyiduna Jundub (may Allah be pleased with him) came, wearing a yellow burnous (the burnous is a cap that people used to wear in the early days of Islam). He said: Continue your conversation as you were. When it was Sayyiduna Jundub’s turn (meaning he had to speak), he removed the burnous from his head and said: I have come to you only with the intention of narrating to you a hadith of your Prophet. The Messenger of Allah (peace and blessings be upon him) sent a Muslim army against a group of polytheists, and they met (i.e., confronted each other on the battlefield). Among the polytheists was a man who would attack and kill any Muslim he wished. Eventually, a Muslim saw him in a state of heedlessness. And people told us (that) the Muslim was Sayyiduna Usamah bin Zaid (may Allah be pleased with him). When he raised his sword against him, the man said: La ilaha illallah (There is no god but Allah), but he killed him. Afterwards, a messenger came to the Messenger of Allah (peace and blessings be upon him) with glad tidings. The Prophet (peace and blessings be upon him) asked him about the situation, and he narrated everything, including the incident of that man. The Prophet (peace and blessings be upon him) called him and asked: Why did you kill him? Sayyiduna Usamah (may Allah be pleased with him) said: O Messenger of Allah! He caused much harm to the Muslims, killed so-and-so and so-and-so, and mentioned several people. Then, when I overpowered him and he saw the sword, he said: La ilaha illallah. The Messenger of Allah (peace and blessings be upon him) said: Did you kill him? He replied: Yes. The Prophet (peace and blessings be upon him) said: What will you answer to La ilaha illallah when it comes on the Day of Resurrection? He said: O Messenger of Allah! Pray for my forgiveness! The Prophet (peace and blessings be upon him) said: What will you answer to La ilaha illallah when it comes on the Day of Resurrection? Then the Prophet (peace and blessings be upon him) did not say anything more than this, and kept repeating: What will you answer to La ilaha illallah when it comes on the Day of Resurrection?