Jami' at-Tirmidhi
Jami` at-Tirmidhi 2942
حَدَّثَنَا مَحْمُودُ بْنُ غَيْلاَنَ، قَالَ حَدَّثَنَا أَبُو دَاوُدَ، قَالَ أَخْبَرَنَا شُعْبَةُ، عَنْ مَنْصُورٍ، قَالَ سَمِعْتُ أَبَا وَائِلٍ، عَنْ عَبْدِ اللَّهِ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " بِئْسَمَا لأَحَدِهِمْ أَوْ لأَحَدِكُمْ أَنْ يَقُولَ نَسِيتُ آيَةَ كَيْتَ وَكَيْتَ بَلْ هُوَ نُسِّيَ فَاسْتَذْكِرُوا الْقُرْآنَ فَوَالَّذِي نَفْسِي بِيَدِهِ لَهُوَ أَشَدُّ تَفَصِّيًا مِنْ صُدُورِ الرِّجَالِ مِنَ النَّعَمِ مِنْ عُقُلِهِ " . هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ .
Unreviewed translation. All hadiths in this collection are available in five languages. Titles and introductions may remain in Arabic.
‘Abd Allah reported that the Prophet said, ‘How terrible it is for one of you to say, “I forgot such-and-such a verse.” Rather, he was made to forget it. Keep revising the Qur’an, for by the One in whose hand is my soul, it slips from people’s hearts faster than a camel breaks free of its tether.’ Abu ‘Isa graded this hadith hasan sahih.
Notes and open questions — unreviewed
The Arabic says ‘he was made to forget’ (nussiya), a passive formulation, rather than simply ‘he forgot.’ The comparison is to a camel escaping its hobble or tether, emphasizing how quickly memorized Qur’an can slip from memory without review.