Musnad Abu Ya'la al-Mawsili 152:36

Al-Hasan ibn Hammad narrated to us, Ibn Abi Ghaniyah narrated to us, from his father, from ‘Asim, from Zirr, from ‘Abdullah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, some poetry is wisdom."