Srimadhbhagvad Gita’s 2nd chapter is Sankhya Yoga. In this Lord Krishna tells Arjuna the cause of eruption of anger and its bad effects.
श्लोक 2.62
ध्यायतो विषयान्पुंसः सङ्गस्तेषूपजायते।
सङ्गात् संजायते कामः कामात् क्रोधोऽभिजायते।।
श्लोक 2.63
क्रोधाद्भवति सम्मोहः सम्मोहात्स्मृतिविभ्रमः।
स्मृतिभ्रंशाद् बुद्धिनाशो बुद्धिनाशात्प्रणश्यति।।
Krishna says that when a person keeps thinking of vishayas (material things), he starts getting attachment for them. This attachment develops desire or expectations for acquiring these objects of comfort & sensual happiness. Any obstruction or non-fulfilment of desires leads to Anger. In Srimadbhagvat Purana, it is termed as younger brother of desires (kama- anujeyan). Anger has a element of proud (Ahamkaar) also, the reason that makes it more bad. If a person’s desire is not fulfilled and he thinks himself to be incapable or weak, he will develop the feeling of sorrow or dejection and may not get angry. Anger develops with the feeling that the person is capable and can get away with his power & capabilities as a doer. Lord Krishna says anger leads to unstable state of mind where person’s mind does not differentiate between good & bad and only thinks of me & mine. In this condition he starts losing memory i.e. any important & critical facts needed to make right decision are forgotten in this state. The logical portion of decision making is lost which is called Buddhi. In this situation, the person suffers losses & destroys himself spiritually & physically.
Anger is something which is difficult to control even sometimes by liberated souls. It can’t be learnt to manage overnight. It needs practice with the principles of religion of forgiveness (Satya, Tapa, Gyan, Kshma) and accepting all situations of loss & gain, life & death, insult & praise as the grace of God. This was reflected in the sacrifice of 5th Guru of Sikhs Guru Arjan Dev. When he was inflicted torture with putting of hot sand on the body and making to sit on hot iron plate, his entire body was badly burnt. At that time, his spiritual friend Mia Mir came and got angry to see the so painful situation. He asked Guru ji to do something against this act of cruelty as Guru ji so capable to even turn the earth upside down. If Guru ji didn’t want then he will teach these perpetrators a lesson with his 2 edged sword. Then Guru ji said with a serene smile that Mia Mir you once asked me is there any person on this earth who accepts life-death, insult-praise, soil-gold as same. You can see this now, am accepting this as will of God. In this suffering Guru ji wrote following verses where he was not asking relief from God rather begging to recite his name.
ਤੇਰਾ ਕੀਆ ਮੀਠਾ ਲਾਗੈ ॥
तेरा कीआ मीठा लागै ॥
ਹਰਿ ਨਾਮੁ ਪਦਾਰਥੁ ਨਾਨਕੁ ਮਾਂਗੈ ॥੨॥੪੨॥੯੩॥ ਰਹਾਉ ॥
हरि नामु पदारथु नानकु मांगै ॥२॥४२॥९३॥रहाउ ॥
Teraa Kiya meetthaa laage,
Har naam padaarath Nanak maangai. (Rahaa-u)
Whatever You do seems sweet to me, O Lord.
Nanak begs for the treasure of the Naam (Name of the Lord).
Hare Krishna!!