A Pearl of Wisdom from al-Mutanabbi

Al-Mutanabbī said:

وَلَمْ ‌أَرَ ‌فِي ‌عُيُوبِ ‌النَّاسِ عَيْبًا

كَنَقْصِ الْقَادِرِينَ عَلَى التَّمَام

I have never seen such a flaw quite like a person who is capable of fixing a deficiency and fails to do so.

(Iḥya ʿUlūm al-Dīn, 4:68)