Abu Jamrah (may Allah have mercy on him) said: I said to Ibn Abbas (may Allah be pleased with them both): "I am a man who recites very quickly, and sometimes I recite the whole Qur'an once or twice in a single night." Ibn Abbas (may Allah be pleased with them both) said: "That I should recite a single surah is dearer to me than doing what you do. If you do such a thing, then recite in a way that your ears can hear and your heart retains it."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4715