Thirukkural-On Virtue-Control Of Temper-Kural -305

If you would protect yourself, guard against your own anger; For, anger not controlled would lead to self-destruction.

It is self-protection to control one's anger, as uncontrolled anger can lead ultimately to self-destruction. The word 'Kollum' (would kill), according to Parimelalagar, is used by the poet in the sense of bringing in its wake, incalculable harm. It is said that the proud man offends God, the envious man wrongs his neighbour and the angry man destroys himself. It is foolish, therefore, to fly into a rage. The Bible mentions a similar idea in the Book of the Proverbs:

'A fool gives full vent to his anger;
but a wise man quietly holds it back'

(Proverbs 29:11)

the Bhagavad Gita would say that the true 'Muni' is one who has eschewed affection, fear and wrath.
(Gita:2, 56)

Seneca has recorded that 'anger' leads to 'mutual destruction'.