Knowledge is the most miserly thing ....

At this moment you are in this place at (your) differing levels – from them the high (levels) and from them lesser than that. However regardless of where the person reaches in knowledge, then he is (still) in need of knowledge – as per the statement of Allaah, the Blessed and Most High: But over all those endowed with knowledge is the All Knowing One (Allaah) [12:76].

Therefore I urge you to have a general eagerness in pursuing (your) studies; and that you know with certain knowledge that the person who does not strive with all his efforts in attaining knowledge, then knowledge in its entirety will slip away from him.

And therefore it is said: indeed knowledge is the most miserly thing there is! For if you give it your all, you will attain (only) some of it; and if you give it only some (of your all), then it will elude you entirely. And therefore I urge you, O young people, to have a complete eagerness for knowledge.

— Muhammad ibn Saalih al ‘Uthaymeenraheemahullah addressing students of Muhammad ibn Sa’ood Islamic University. (via shuayyb)