Musannaf Ibn Abi Shayba 22:24

Muhammad ibn Bishr narrated to us, he said: Mis'ar narrated to us, from Sulayman al-Dabbi, from Ibrahim, from Alqama or al-Aswad, from Abdullah, who said: "Whoever recites the Quran, seeking by it the Face of Allah, will have for every letter ten good deeds and the erasure of ten bad deeds."