Kural - 459

Although to mental goodness joys of other life belong,
Yet good companionship is confirmation strong

Explanation
Future bliss is (the result) of goodness of mind; and even this acquires strength from the society of the good.

Tamil Transliteration
Mananalaththin Aakum Marumaimar Raqdhum
Inanalaththin Emaap Putaiththu.