Musnad Ahmad 121:2

Ya'qub narrated to us, my father narrated to us, from Ibn Ishaq, who said: Muhammad ibn Ibrahim ibn al-Harith al-Taymi narrated to us, from Abu al-Haytham ibn Nasr ibn Dahr al-Aslami, that his father narrated to him that he heard the Messenger of Allah, peace and blessings of Allah be upon him, say during his march to Khaybar to 'Amir ibn al-Akwa'—and he was the paternal uncle of Salamah ibn 'Amr ibn al-Akwa', and the name of al-Akwa' was Sinan—: "Dismount, O son of al-Akwa', and chant for us some of your little verses." He said: So he dismounted, chanting *rajaz* poetry for the Messenger of Allah, peace and blessings of Allah be upon him, saying: "By Allah, were it not for Allah, we would not have been guided, Nor would we have given charity, nor would we have prayed. Indeed, if a people oppress us, And if they desire discord, we refuse. So send down tranquility upon us, And make firm the feet if we meet [the enemy]."