Abu Qatada said God’s Messenger went out one night and found Abu Bakr praying in a low voice, and he passed ‘Umar who was raising his voice while praying. When they both were with the Prophet he said, “I passed you, Abu Bakr, when you were praying in a low voice.” He replied, “I made Him hear with whom I was holding intimate converse, Messenger of God.” He said to ‘Umar, “I passed you when you were raising your voice while praying.” He replied, “Messenger of God, I was wakening the drowsy and driving away the devil.” The Prophet said, “Raise your voice a little, Abu Bakr;” and he said to ‘Umar, “Lower your voice a little.”
Abu Dawud transmitted it, and Tirmidhi transmitted something similar.
Narrated ‘Abdallah b. ‘Amr b. al-‘As reported God’s Messenger as saying, “If anyone makes proper use of ten verses he will not be recorded among the negligent; if anyone makes proper use of a hundred verses he will be recorded among those who are obedient to God:
and if anyone makes proper use of a thousand verses he will be recorded among those who receive huge rewards.”