Sham al-Hawaa by Ibn al-Jawzi, p.8
“hazrat umar jo the top ke sahabi the lekin har lamha woh kaanpte the kya hoga marne ke baad is ka nateeja kya hua un ka dimagh mein itni taraqqi itna zyada development hua tha kitni bari bari batein kahi unhon ne ke aaj bhi musalmanon ko pata nahi in baton ka unhon ne kaha tha ke less al aaqil alladhi ya'rif al khair min al sharr walaak alladhi ya'rif khair al sharrrain”