Kural - 399

Their joy is joy of all the world, they see; thus more
The learners learn to love their cherished lore

Explanation
The learned will long (for more learning), when they see that while it gives pleasure to themselves, the world also derives pleasure from it.

Tamil Transliteration
399 Thaamin Puruvadhu Ulakin Purak Kantu
Kaamuruvar Katrarin Thaar.