Musnad Ahmad 5:255

'Affan narrated to us, Khalid—meaning al-Tahhan—narrated to us, Mutarrif narrated to us, from Abu Ishaq, from al-Harith, from 'Ali, who said: "The Messenger of Allah (ﷺ) forbade a man from raising his voice with the Qur'an before the 'Atamah (night prayer) and after it, so that he does not confuse his companions in their prayer."