It is narrated from Sayyiduna Uqbah bin Amir (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "The one who recites the Qur'an quietly is like the one who gives charity secretly, and the one who recites the Qur'an aloud is like the one who gives charity openly."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 14994