وَعَنْ أَبِي الدَّرْدَاءِ
قَالَ: «إِنَّ مِنْ أَشَرِّ النَّاسِ عِنْدَ اللَّهِ مَنْزِلَةً يَوْمَ الْقِيَامَةِ: عَالِمٌ لَا ينْتَفع بِعِلْمِهِ»
The one who would have the worst position in God’s sight on the day of resurrection would be a learned man who did not profit from his learning.
Mishkat al-Masabih 253, Book 3, Knowledge, Hadith 64. 1 min read