Sunnan Abu Dawud Collection :: Book Number 5
5.1324
Narrated AbuQatadah: The Prophet (peace_be_upon_him) went out at night and found AbuBakr praying in a low voice, and he passed Umar ibn al-Khattab who was raising his voice while praying. When they both met the Prophet (peace_be_upon_him) together, the Prophet (peace_be_upon_him) said: I passed by you, AbuBakr, when you were praying in a low voice. He replied: I made Him hear with Whom I was holding intimate converse, Apostle of Allah. He (the Prophet) said to Umar: I passed by you when you were praying in a loud voice. He replied: Apostle of Allah, I was awakening the drowsy and driving away the Devil. Al-Hasan added in his version: The Prophet (peace_be_upon_him) said: Raise your voice a little, AbuBakr, and he said to Umar: Lower your voice a little.