Prayer (Kitab Al-Salat): Prayer at Night
Dawud :: Book 5 : Hadith 1327
Narrated AbuSa'id al-Khudri:
The Apostle of Allah (peace_be_upon_him) retired to the mosque. He heard them (the people) reciting the Qur'an in a loud voice. He removed the curtain and said: Lo! every one of you is calling his Lord quietly. One should not trouble the other and one should not raise the voice in recitation or in prayer over the voice of the other.