Musnad Abu Ya'la al-Mawsili 6:128

Ahmad ibn Ibrahim al-Nukri narrated to us, Bahz ibn Asad narrated to us, Shu'bah narrated to us, Qatadah narrated to us, from Yunus ibn Jubayr, from Muhammad ibn Sa'd ibn Abi Waqqas, from his father, that the Messenger of Allah (may Allah bless him and grant him peace) said: "For the interior of one of you to be filled with pus is better for him than for it to be filled with poetry."