Sunan At-Tirmidhi

Narrated Abu Idris Al-Khawlani:""When 'Umar bin Al-Khattab removed 'Umair bin Sa'd as governor of Hims, he appointed Mu'awiyah. The people said: 'He has removed 'Umair and appointed Mu'awiyah.' So 'Umair said: 'Do not mention Mu'awiyah except with good, for indeed, I heard the Messenger of Allah (ﷺ) saying: ""O Allah guide (others) by him