byLajnah Da'imah Lil Buhuts Al-Ilmiah Wal Ifta
Lajnah Da'imah Lil Buhuts Al-Ilmiah Wal Ifta asked: Someone has memorized five juz of the Quran, but because a lot of busy, he does not repeat their Qur'an memorize in long time so that the occasion is lost, and he forgot. How is legal, whether the sinner? Are there any hadiths threatening thing like this?
Praise be to Allah, prayers and greetings may be delegated to His Apostle and his family and companion, wa ba'du.
The person should be advised and encouraged to re-learn the whole of Quran, read it, download it and practice it. He also needs to be warned against the harmful effects of too much concern themselves with the world so that forgetting his religious affairs.
As for the hadith that has threats against those who had memorized the Qur'an then he forgot, the hadith is Da'eef.
Wabillah at-taufiq sallallaahu wa 'ala Muhammad wa nabiyyina aalihi shahbihi wa sallam.
[Copied from the book Fatwa FII Ihtiraamil Qur'an 70, edition of Indonesia 70 Fatwa On Al-Quran, Composer Abu Anas Abu Ali ibn Husayn Luz, publisher Dar al Haq]