Narrated Hasan (r.a)

 Knowledge is of two types

1- Firstly, knowledge perceived by the heart, and that is useful knowledge; 
2- Secondly, the knowledge at on the tip of one’s tongue, and that is an argument from Allah, the Exalted and Glorious, against the children of Adam.


Al-Tirmidhi – Hadith 270

Narrated AbuHurayrah (r.a) :

Allah’s Messenger (peace be upon him) said: 

The knowledge from which no benefit is derived is like a treasure out of which nothing is spent in the cause of Allah.

Al-Tirmidhi – Hadith 280