Musnad Ahmad 145:4

'Affan narrated to us, Aban narrated to us, Yahya ibn Abi Kathir narrated to us, from Zayd, from Abu Sallam, from Abu Rashid al-Hubrani, from 'Abd al-Rahman ibn Shibl al-Ansari, that Mu'awiyah said to him: "When you come to my tent, stand and inform [the people] of what you heard from the Messenger of Allah, may Allah bless him and grant him peace." He said: I heard the Messenger of Allah, may Allah bless him and grant him peace, saying: "Read the Quran, and do not exceed the limits in it, and do not turn away from it, and do not consume [wealth] by means of it, and do not seek to increase [your worldly gain] through it."