Mus'ab bin Sa'd narrated that his father said:
"The Messenger of Allah said: 'The best of you is the one who learns the Qur'an and teaches it.' " 'Then he (Mus'ab) took me (the narrator) by the hand and made me sit here, and I started to teach Qur'an.'" (ID)
English reference (ID): Vol. 1, Book 1, Hadith 213 (ID)
Arabic reference (ID): Book 1, Hadith 218 (ID)