A Brahmana had two sons - Paravasu & Arvavasu.He gave equal knowledge to both Once Paravasu, travelling in the jungle saw a beast of prey. He hurled his spear & killed the beast.But to his horror discovered that he had mistakenly killed his own father clad in skin. He hurriedly went to Aravavasu & narrated the saga.He asked Arvavasu to proxy perform father's obsequial rites & atone his sin.Parvavasu could manage father's duty unaided which Arvavasu could not.That was the reason. The virtuous Arvavasu agreed. Later upon return, he seeks to join the King's duty.To his utter surprise, Parvavasu protested & blamed Arvavasu of killing their father. The King was angry. The explanations of proxy atonement were found to be bizairre. Traduced as a liar & killer, he was banished to the jungles. In anger & despair of finding justice in the world, Arvavasu went into deep meditation, undertaking rigorous austerities.The Gods were pleased & granted him a boon Arvavasu had cleansed himself of anger by then. Whilst Gods expected otherwise, he sought for their father to be restored to life & for his dear brother to be freed from wickedness & the sins he had committed Both brothers knowledgable equally but one had virtues. And that made the critical difference