Thirukkural – 302
Anger where one is powerless is bad; where
one is powerful, it is even worse.
செல்லா இடத்துச் சினம் தீது; செல் இடத்தும்,
இல், அதனின் தீய பிற.
Anger destroys a man. Showing anger against a stronger opponent is bad news. It will be disastrous for you in this world. Showing anger against the meek is even worse. Showing your anger against those who can’t fight back destroys the humanity in man kind. It will make one suffer in afterlife too.