Kural - 579

To smile on those that vex, with kindly face,
Enduring long, is most excelling grace

Explanation
Patiently to bear with, and show kindness to those who grieve us, is the most excellent of all dispositions.

Tamil Transliteration
Oruththaatrum Panpinaar Kannumkan Notip
Poruththaatrum Panpe Thalai.