Musnad Ahmad 30:756

Al-Fadl ibn Dukayn narrated to us, Sufyan narrated to us, from al-A'mash, from Dhakwan, from Abu Hurayrah, who said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "For the interior of a man to be filled with pus that consumes him is better for him than for it to be filled with poetry."