عن أنس بن مالك، قال: قال رسول الله صلى الله عليه وسلم: عرضت علي أجور أمتي حتى القذاة يخرجها الرجل من المسجد، وعرضت علي ذنوب أمتي، فلم أر ذنبا أعظم من سورة من القرآن أو آية أوتيها رجل ثم نسيها (سنن أبي داود، الرقم: 461)
Hazrat Anas bin Maalik (radhiyallahu ‘anhu) reports that Rasulullah (sallallahu ‘alaihi wasallam) said, “The rewards of the good deeds of my Ummah were presented before me, to the extent (that I was shown the reward) of a person picking up a small piece of dirt which was lying in the musjid, and the sins of my Ummah were presented before me, and I did not see any sin greater than the sin of a person who forgot a surah or an aayah of the Quraan Majeed which he was blessed with.”
Note:
1. In this Hadith, the sin of forgetting an aayah or surah of the Quraan Majeed is explained to be the worst of sins. The reason for this is that one is showing ingratitude to Allah Ta‘ala for this great bounty of the Quraan Majeed by neglecting its recitation and thereby forgetting what one had been blessed with.
2. Some Ulama have explained that the admonition explained in this Hadith is for the one who neglects the recitation of the Quraan Majeed and forgets what he had committed to memory.
Other Ulama hold the opinion that this admonition is for the one who neglects the recitation of the Quraan Majeed to the extent that he not only forgets what he had committed to memory, but also forgets how to recite the Quraan Majeed.