Musnad Ahmad 1153:771

Aswad ibn Amir narrated to us, he said: Shu'bah narrated to us, from Qatadah, he said: I heard Zurarah ibn Awfa narrating from Sa'd ibn Hisham, from Aisha, from the Prophet, may Allah bless him and grant him peace, who said: "The likeness of the one who recites the Quran and commits himself to it, while it is difficult for him, has two rewards." He said: "And the likeness of the one who recites the Quran and is a memorizer of it, is like the noble, righteous scribes."