Kural - 96

Who seeks out good, words from his lips of sweetness flow;
In him the power of vice declines, and virtues grow

Explanation
If a man, while seeking to speak usefully, speaks also sweetly, his sins will diminish and his virtue increase.

Tamil Transliteration
Allavai Theya Aramperukum Nallavai
Naati Iniya Solin.