குறள் 313

செய்யாமல் செற்றார்க்கும் இன்னாத செய்தபின்
உய்யா விழுமந் தரும்.

Stanza 313

Vengeance even against a wanton insult

Does endless damage.

Meaning:

If a man inflicts suffering even on those who hate him, without having been injured by him; it will afterwards give him irremovable sorrow.