Musnad Ahmad 924:1

Yazid ibn Harun narrated to us, Ibrahim ibn Sa'd informed us, from al-Zuhri, from Abu Bakr ibn Abd al-Rahman ibn al-Harith ibn Hisham, from Marwan ibn al-Hakam, from Ibn al-Aswad ibn Abd Yaghuth, from Ubayy ibn Ka'b, that the Messenger of Allah, peace and blessings of Allah be upon him, said: "Indeed, some poetry is wisdom."