Abu Dawud Book 2, Hadith Number 1328.
Chapter : Recitation of the quran in loud voice during the prayer at night.
Narated By Uqbah ibn Amir al-Juhani : The Prophet (PBUH) said: One who recites the Qur’an in a loud voice is like one who gives alms openly; and one who recites the Qur’an quietly is one who gives alms secretly.