Kural - 318

Whose soul has felt the bitter smart of wrong, how can
He wrongs inflict on ever-living soul of man

Explanation
Why does a man inflict upon other creatures those sufferings, which he has found by experience are sufferings to himself ?.

Tamil Transliteration
Thannuyirkaku Ennaamai Thaanarivaan Enkolo
Mannuyirkku Innaa Seyal.