Musnad Ahmad 28:138

Hassan narrated to us, Ibn Lahi'ah narrated to us, Huyayy ibn Abdullah narrated to me, from Abu Abd al-Rahman al-Hubuli, from Abdullah ibn Amr, that a man came to the Prophet, may God bless him and grant him peace, with a son of his. He said: "O Messenger of God, this son of mine recites the Mushaf during the day, and spends the night sleeping." The Messenger of God, may God bless him and grant him peace, said: "What do you find fault with, that your son spends his day remembering [God], and spends his night safe?"