The narrator narrates that Marwan bin al-Hakam was fighting al-Dahhak bin Qays, and he said to a man of Banu Asad called Ayman bin Khuraym: "Will you not fight alongside us?" He said: "No. My father and my paternal uncle took part in Badr with the Messenger of Allah (peace and blessings be upon him), and they ordered me not to fight anyone who bears witness that there is no god but Allah. If you bring me a guarantee of freedom from the Fire, I will fight alongside you." He said: "Go, we have no need of you." So Ayman recited these verses:
I am not one to kill a man who prays, even if he is under the allegiance of another rule of Quraysh.
His rule is his own responsibility, and my sin is upon me; I seek refuge with Allah from ignorance and folly.
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 848