Abu Khalid, who was one of the companions of Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), narrated: A man came to Sayyiduna Abdullah (may Allah be pleased with him) and said: "O Abu Abd al-Rahman! So-and-so recites the Qur'an while bowing and recites it while prostrating." Sayyiduna Abdullah (may Allah be pleased with him) said: "There are people who recite the Qur'an, but it does not go down past their throats; and when it enters the heart and settles firmly in it, it benefits."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9309