Musnad Abu Ya'la al-Mawsili 245:12

Uthman ibn Muhammad narrated to us, Jarir narrated to us, from Mis'ar, from Mujammi', from Abu Umamah ibn Sahl ibn Hunayf, who said: I heard Mu'awiyah saying: The Messenger of Allah (ﷺ) said: "And he heard the mu'adhdhin, so he said the like of what he said."