Musnad Ahmad 28:282

Abu Kamil and Yunus narrated to us, they said: Nafi' ibn 'Umar narrated to us, from Bishr ibn 'Asim al-Thaqafi, from his father, from 'Abdullah ibn 'Amr—Nafi' said: And I do not know it except from the Prophet, may Allah bless him and grant him peace—['Abdullah ibn Ahmad said]: My father said: And Yunus did not doubt—he said: From the Prophet, may Allah bless him and grant him peace, he said: "Verily, Allah the Almighty and Majestic hates the eloquent among men, who rolls his tongue [in his mouth] as a cow rolls [its tongue] with its tongue."