Q 3: I had memorized some Surahs (Qur'anic chapters), but after a while I became busy and forgot some of them. I try hard not to forget the Qur'an I have memorized but in vain.I read the Hadith in which the Prophet (peace be upon him) stated:
The gravest sin of my Ummah (nation based on one creed) is forgetting the Qur'an.
In addition, one of the Muslim scholars said that memorizing one Surah or one Ayah (Qur'anic verse) and forgetting it is a major sin. What is the degree of authenticity of the previous Hadith? Am I excused or not?
(Part No. 3; Page No. 110
We know of no evidence supporting the authenticity of this Hadith mentioned in the question threatening those who forget the Qur'an or parts of it We do not know it to be authentically reported from the Prophet (peace be upon him). Yet, it is necessary to revise the Qur'an regularly and recite it often, for the Prophet (peace be upon him) encouraged and exhorted his followers to do this.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.