Musnad Abu Ya'la al-Mawsili 40:1

Zahmūyah narrated to us, Sālih ibn ‘Umar narrated to us, from Mutarrif, from ‘Āmir, who said: When Marwān fought al-Dahhāk ibn Qays, he sent to Ayman ibn Khuraym al-Asadī and said, "We would like for you to fight with us." He replied, "My father and my paternal uncle witnessed Badr, and they made a covenant with me that I should not fight anyone who testifies that there is no god but Allah. So, if you bring me a release from the Fire, I will fight with you." He (Marwān) said, "Go away," and he disparaged him and insulted him. So Ayman began to recite: "And I will not fight a man who prays, for the sake of another ruler from Quraysh. He has his authority, and upon me is my sin. I seek refuge in Allah from ignorance and recklessness. Shall I fight a Muslim for nothing? My life will not benefit me as long as I live."