Sayyiduna Sahl bin Sa'd (may Allah be pleased with him) relates that the Messenger of Allah (peace and blessings be upon him) came out to us while we were teaching one another to recite the Qur'an, and he (peace and blessings be upon him) said: "Praise be to Allah, the Book of Allah is one, and among you are the fair and the black. Recite the Qur'an, recite the Qur'an, before there come people who will recite it straight as an arrow is straightened, but it will not go beyond their throats; they will seek its reward hastily and will not defer it."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5998