Thirukkural 479

அளவறிந்து வாழாதான் வாழ்க்கை உளபோல இல்லாகித் தோன்றாக் கெடும்.

Alavariindhu vaazhaadthaan vaazkai ulapol Illaakith thoondaak kedum.

A life lived without knowing measure will perish outwardly while appearing to stand—hollow at the core, it crumbles to nothing.