[5/1545] al-Kafi: A number of our companions from Ahmad b. Muhammad and Sahl b. Ziyad all together from Ibn Mahbub from Jamil b. Salih from al-Fudhayl b. Yasar from Abi Abdillahعليه السلام. He (Fudhayl) said: I heard him (i.e. the Imam) say:

The one who labours over the Qur’an and memorizes it with great difficulty on his part and having poor memory - for him is double the reward