The story of forgiveness is greater than revenge in Hinduism was narrated to the Pandavas during their exile period in the Vana Parva of Mahabharata by Rishis. They had met Rishis on the advice of Indra who wanted Pandavas to use their years of exile wisely to travel, see new places, and learn new skills and to spend time with sages and learned people. This would help them in becoming better human beings and rulers.
Once a sage called Raibhya found his daughter-in-law having an illicit relationship with young man named Yavakri. This enraged the sage and he soon caught her in the arms of Yavakri. Raibhya could not tolerate this indiscretion and he killed Yavakri.
Bharadvaja, father of Yavakri, cursed Raibhya that he would die at the hand of his own son, Paravasu.
The curse came true a few days later when Paravasu, who used to go for hunting in deep forest, mistaking his father for a wild animal, killed him.
To save himself, Paravasu accused his brother, Aravasu, who had accompanied him into deep forest, of patricide.
Although Aravasu protested his innocence, no one believed him. Thus everyone believed he had killed his father.
Angry and disillusioned, Aravasu retreated to the forest, here he performed severe austerities to gain occult powers so that he could clear his reputation and teach his brother a lesson.
But as he learned ways of life, experiences of others and heard stories from Rishis, his mind slowly reached a state of wisdom. Soon all the desire for revenge melted away. His mind was at peace, he realized that there was a far greater joy in forgiving than in revenge.