Kural - 320

O'er every evil-doer evil broodeth still;
He evil shuns who freedom seeks from ill

Explanation
Sorrow will come upon those who cause pain to others; therfore those, who desire to be free from sorrow, give no pain to others.

Tamil Transliteration
Noyellaam Noiseydhaar Melavaam Noiseyyaar
Noyinmai Ventu Pavar.