(a) It is narrated from Sayyiduna Uthman bin Affan (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "Indeed, the best of you is the one who teaches the Qur'an and also learns it himself."
(b) Abu Abd al-Rahman (may Allah have mercy on him) taught the Qur'an during the caliphate of Sayyiduna Uthman (may Allah be pleased with him) until the time of al-Hajjaj came. He said: It is this teaching of the Qur'an that has brought me to this position.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2272