Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:16:70 –

And Allah created you; then He will take you in death. And among you is he who is reversed to the most decrepit ˹old˺ age so that he will not know, after ˹having had˺ knowledge, a thing. Indeed, Allah is Knowing and Competent.  

And God has created you, when you were nothing, then He takes you ˹in death˺, when your terms ˹of life˺ are concluded; and there are some among you who are relegated to the most abject stage of life, that is, the most diminished, because of old-age and senility, so that he knows nothing after ˹having possessed˺ some knowledge. ‘Ikrima said, ‘Whoever recites the Qur’ān will not come to such a predicament’. God is Knowing, of how to manage ˹the affairs of˺ His creation, Powerful, in ˹doing˺ what He will.
القرآن:١٦:٧٠ –

وَاللَّهُ خَلَقَكُمْ ثُمَّ يَتَوَفَّاكُمْ ۚ وَمِنْكُمْ مَنْ يُرَدُّ إِلَىٰ أَرْذَلِ الْعُمُرِ لِكَيْ لَا يَعْلَمَ بَعْدَ عِلْمٍ شَيْئًا ۚ إِنَّ اللَّهَ عَلِيمٌ قَدِيرٌ  

{والله خلقكم} ولم تكونوا شيئاً {ثم يتوفاكم} عند انقضاء آجالكم {ومنكم من يرد إلى أرذل العمر} أي أخسه من الهرم والخرف {لكي لا يعلم بعد علم شيئاً} قال عكرمة من قرأ القرآن لم يصر بهذه الحالة {إن الله عليم} بتدبير خلقه {قدير} على ما يريده.