May Allah show mercy to him; he has reminded me of such and such a verse which I had missed in such and such a surah.  

أَنَّ النَّبِيَّ ﷺ سَمِعَ رَجُلاً يَقْرَأُ مِنَ اللَّيْلِ فَقَالَ يَرْحَمُهُ اللَّهُ لَقَدْ أَذْكَرَنِي كَذَا وَكَذَا آيَةً كُنْتُ أَسْقَطْتُهَا مِنْ سُورَةِ كَذَا وَكَذَا  

May Allah have mercy upon him; be reminded me of the verse which I had been made to forget.  

كَانَ النَّبِيُّ ﷺ يَسْتَمِعُ قِرَاءَةَ رَجُلٍ فِي الْمَسْجِدِ فَقَالَ رَحِمَهُ اللَّهُ لَقَدْ أَذْكَرَنِي آيَةً كُنْتُ أُنْسِيتُهَا  

The example of a man who has memorised the Qur'an is like that of a hobbled camel. If he remained vigilant, he would be able to retain it (with him), and if he loosened the hobbled camel it would escape.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِنَّمَا مَثَلُ صَاحِبِ الْقُرْآنِ كَمَثَلِ الإِبِلِ الْمُعَقَّلَةِ إِنْ عَاهَدَ عَلَيْهَا أَمْسَكَهَا وَإِنْ أَطْلَقَهَا ذَهَبَتْ  

" When one who had committed the Qur'an to memory (or who is familiar with it) gets up (for night prayer) and recites it night and day, it remains fresh in his mind, but if he does not get up (for prayer and thus does not recite it) he forgets it."  

عَنِ النَّبِيِّ بِمَعْنَى حَدِيثِ مَالِكٍ وَزَادَ فِي حَدِيثِ مُوسَى بْنِ عُقْبَةَ وَإِذَا قَامَ صَاحِبُ الْقُرْآنِ فَقَرَأَهُ بِاللَّيْلِ وَالنَّهَارِ ذَكَرَهُ وَإِذَا لَمْ يَقُمْ بِهِ نَسِيَهُ  

What a wretched person is he amongst them who says: I have forgotten such and such a verse. (He should instead of using this expression say): I have been made to forget it. Try to remember the Qur'an for it is more apt to escape from men's minds than a hobbled camel.  

قَالَ رَسُولُ اللَّهِ ﷺ بِئْسَمَا لأَحَدِهِمْ يَقُولُ نَسِيتُ آيَةَ كَيْتَ وَكَيْتَ بَلْ هُوَ نُسِّيَ اسْتَذْكِرُوا الْقُرْآنَ فَلَهُوَ أَشَدُّ تَفَصِّيًا مِنْ صُدُورِ الرِّجَالِ مِنَ النَّعَمِ بِعُقُلِهَا  

Keep refreshing your knowledge of the sacred books (or always renew your knowledge of these sacred books) and sometimes he would mention the Qur'an for it is more apt to escape from men's minds than animals which are hobbled, and the Messenger of Allah ﷺ said: None of you should say: I forgot such and such a verse, but he has been made to forget.  

عَبْدُ اللَّهِ تَعَاهَدُوا هَذِهِ الْمَصَاحِفَ وَرُبَّمَا قَالَ الْقُرْآنَ فَلَهُوَ أَشَدُّ تَفَصِّيًا مِنْ صُدُورِ الرِّجَالِ مِنَ النَّعَمِ مِنْ عُقُلِهِ قَالَ وَقَالَ رَسُولُ اللَّهِ ﷺ لاَ يَقُلْ أَحَدُكُمْ نَسِيتُ آيَةَ كَيْتَ وَكَيْتَ بَلْ هُوَ نُسِّيَ  

Wretched is the man who says: I forgot such and such a sura, or I forget such and such a verse, but he has been made to forget.  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ بِئْسَمَا لِلرَّجُلِ أَنْ يَقُولَ نَسِيتُ سُورَةَ كَيْتَ وَكَيْتَ أَوْ نَسِيتُ آيَةَ كَيْتَ وَكَيْتَ بَلْ هُوَ نُسِّيَ  

Keep refreshing your knowledge of the Qur'an, for I swear by Him in Whose Hand is the life of Mahammad that it is more liable to escape than camels which are hobbled.  

عَنِ النَّبِيِّ ﷺ قَالَ تَعَاهَدُوا هَذَا الْقُرْآنَ فَوَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ لَهُوَ أَشَدُّ تَفَلُّتًا مِنَ الإِبِلِ فِي عُقُلِهَا وَلَفْظُ الْحَدِيثِ لاِبْنِ بَرَّادٍ