Musnad Ahmad 658:237

Waki' narrated to us, al-A'mash narrated to us, and Ibn Numayr narrated to us, al-A'mash informed us, from Talhah ibn Musarrif, from 'Abd al-Rahman ibn 'Awsajah, from al-Bara' ibn 'Azib, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Adorn the Qur'an with your voices."