Allah tells us that the longer the son of Adam lives, the more he becomes weak after being strong, and incapable after being able and active

This is like the Ayah:

اللَّهُ الَّذِى خَلَقَكُمْ مِّن ضَعْفٍ ثُمَّ جَعَلَ مِن بَعْدِ ضَعْفٍ قُوَّةٍ ثُمَّ جَعَلَ مِن بَعْدِ قُوَّةٍ ضَعْفاً وَشَيْبَةً يَخْلُقُ مَا يَشَآءُ وَهُوَ الْعَلِيمُ الْقَدِيرُ

Commentary

In the first verse cited here, it was said: وَمَا عَلَّمْنَاهُ الشِّعْرَ‌ وَمَا يَنبَغِي لَهُ (And We did not teach him poetry and it is not proper for him.) Since the deniers of the appearance of a prophet and messenger with a mission could not deny the unique effectiveness of the Qur'an and its ability to move hearts that was a matter of common experience, therefore, they invented convenient excuses. At times, they would call this Divine Word, some magic and the Holy Prophet ﷺ ، a magician. Then, on other occasions, they would say that this Word was poetry and he was a poet. By saying that, they wanted to prove that this unique effectiveness did not come out of the Divine Word as such, instead, they were either words of magic or sorcery that made an impression on hearts, or it is poetic speech for that too affects hearts.