Sayyiduna Nasr bin Dahr al-Aslami (may Allah be pleased with him) narrates that, at the time of setting out for Khaybar, he heard the Prophet (peace and blessings be upon him) say to Sayyiduna Amir bin al-Akwa' (may Allah be pleased with him), who was the paternal uncle of Sayyiduna Salamah bin Amr bin al-Akwa' (may Allah be pleased with him) (al-Akwa''s name was Sinan), (the Prophet (peace and blessings be upon him) said): "O Ibn al-Akwa'! Get down and sing us a camel-song from your chants." The narrator says: He got down and began to recite this rajaz for the Prophet (peace and blessings be upon him): "By Allah, were it not for Allah, we would not have been guided, nor would we have given charity, nor would we have prayed. Our situation is that the enemy is bent on transgression against us; he intends trial (that is, war), and we refuse it. (O our Lord!) Send down tranquillity upon us, and keep our feet firm if we face (the enemy on the battlefield)."
Ahmad and al-Tabarani recorded it, and al-Tabarani added these words: The Prophet (peace and blessings be upon him) said: "May Allah Almighty have mercy on you!" Sayyiduna Umar (may Allah be pleased with him) said: "O Messenger of Allah! By Allah, (death or martyrdom) has become certain for this man. If only you had let us benefit from him (that is, prayed for his life, it would have been good)." That man was martyred on the occasion of the Battle of Khaybar. The narrators of both narrations are thiqat (trustworthy).