What is anger? It is a vindictive attitude towards sentient beings, towards frustration, and towards that which gives rise to one's frustrations. It functions to serve as a basis for fault-finding and for never finding even a moment of happiness.
Anger is a vindictive attitude which is unable to accept the three situations that may give rise to anger and which inflicts suffering on the three situations.-Abhidharmasamuccaya
The three situations of anger are sentient beings, one's personal frustrations, and the situation from which these frustrations come.
The reason for saying that the foundation of a vindictive attitude is ninefold is in accordance with the Ratnamala which says,
The vindictive mind comes from nine causesHere the lam-rim states,
Which are vindictiveness towards one's self,
One's friends, and one's enemy in the three
Aspects of time and other unfounded fears.
Anger does not allow one to settle on the pleasures of this life and produces immeasurable frustrations in the next life. Thus, the Bodhicaryavatara states,Anger is to feel vindictive about sentient beings, frustration, and such things that annoy one such as weapons and thorns. It is a fierce mind which is intent on getting even with all of this.
The Jatakamala states,When one is mentally feverish with hate,
The mind cannot experience peace.
In not being able to gain either happiness or joy
One will lose sleep and become very unsteady.He who with whatever wealth or honor
Does kindness will become steadfast.
They are the assailants who slay
That tyrant ruler, hatred.By anger friends are made weary, and even if one attracts
Them by gifts, they cannot be made to stay.
In short, anger does not offer one
The slightest chance to be happy.
If ones' face is distorted by the fire of anger,
Even ornaments will not make it look beautiful.
Even if one goes to sleep on a comfortable bed,
The mind burning with anger will be miserable.He forgets what good was done for him,
And being afflicted by anger he goes evil ways.
He fails in fame and achievements
And even his prosperity dwindles like the waning moon.Even if he is supported by friends, the angry person
Will fall into ways not suited to being a human.
While only thinking about "How can I get something" or
"How can I harm someone," his intelligence collapses and,
Generally, he violates the moral norm and becomes more and more infatuated.When through anger he has become accustomed to do evil acts,
He will for one hundred years suffer evil forms of life.
Even an enemy who is after the evil-doer
Could not be worse than this!