Story of Upamanyu – Shiva Purana

The chapters 34 & 35 in Section 7.1 of Vayaviya-saṃhita of Shiva Purana elucidated the story of Upamanyu.
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Upamanyu was son of a great sage Vyaghrapada, who was a great Siddha in his former birth.   Once the boy had tasted some quantity of milk in the hermitage of his uncle. He entreated his mother to give cow’s milk. However, the saintly mother, the wife of Vyaghrapada, was not able provide him milk due to poverty. She informed Upamanyu, If Shiva is not pleased, people do not get those pleasing things viz. kingdom, heaven, salvation or a milk diet. Everything is the result of Shiva’s grace and not that of any other lord. The great lord who is the bestower of wealth and befitting benefits to those who desire them, has not been worshipped by us now.
On hearing the words of his mother, Upamanyu said: — “O mother, do not feel unhappy; if there is Shiva, everything good will result. Sooner or later I shall get an ocean of milk.”
Worship him alone with due devotion. “Namaḥ Shivaya” mantra is directly expressive of Shiva, the bestower of boons. Permitted by her he went to the mountain Himavat and performed penance with purity of minds. He took in only wind (no food). With eight bricks he built an altar and installed Shiva’s phallic image of clay. He invoked the unchanging lord Shiva accompanied by the Gaṇas and Parvati. He worshipped him with the leaves and flowers available in the forest repeating the five-syllabled Mantra with devotion. He performed penance for a long time. Though harassed by Raksasa, he somehow maintained his penance. He uttered “Namaḥ Śivaya” like one in great distress. The whole universe including the mobile and immobile beings became ignited due to the penance of that brahmin, the noble Upamanyu.
Then the excellent gods went to Vaikuntha and mentioned everything to Vishnu. Vishnu went to the Mandara mountain and explained Shiva that Upamanyu has burnt everything by his penance for obtaining the milk.
Then, the trident-bearing lord Shiva resolved to go there assuming the form of Indra. Seated on a white elephant Sadashiva in the form of Indra went to the hermitage of the sage. He said: - “O elder brother of Dhaumya, I am delighted with your penance. Mention the boon you wish to have. I shall grant you whatever you desire.” The leading sage when urged in reverence — ‘I request you to grant me the boon of devotion to Shiva’.
On hearing that Indra said: — “you do not know me the lord of gods. O brahminical sage, be my devotee. Always worship only me. Welfare be to you. I shall give you everything. Abandon Rudra who is devoid of attributes.”
On hearing that, the sage began to repeat the five-syllabled Mantra. He thought that Indra had come there to put obstacles in his holy rites and so said. Upamanyu said: — “You do not know Rudra the lord of the chiefs of the gods, the progenitor of Brahma, Vishnu and Shiva and who is greater than Prakriti. I desire to get my boon granted by the lord who is separate from Sat and Asat, who is the unmanifest, as mentioned by the propounders of Brahman and who is eternal, single and multifarious. I desire to secure the boon from that lord whom the knowers of truth meditate upon, who bestows the goal of Saṃkhya and Yoga, viz. release. There is no higher truth than Shiva who is the cause of all causes, the creator of Brahma, Vishnu and other gods and who is the lord beyond attributes.”
After saying this, Upamanyu ready to die himself eschewed his desire for milk and got ready to kill Indra. He took the ash and reinvigorated it with the Aghorastra mantra. Aiming it at Indra, he cast it off and shouted loudly. Remembering the feet of Shiva he attempted to burn off his body. Upamanyu held the fiery missile ready for discharge. Shiva prevented the missile of the Yogi gently. At the behest of the lord, Nandi caught in the middle the Aghorastra hurled by him. Assuming his own form with the crescent moon for his crest, Lord Shiva revealed himself to the brahmin. The Lord showed to him a thousand oceans of milk, nectar curds, ghee, fruits, foodstuffs and a mountain of sweet pies.
Then Upamanyu enveloped by the waves of bliss fell at his feet, his mind made humble with devotion. Then the smiling lord Shiva called him nearer, kissed him on the head and granted him boons. Shva said: — “Be my devotee. This goddess Parvati is your mother. You have been adopted as my son. The milk ocean is given to you. So also, the ocean of honey, of rice with curds and ghee and of fruits etc. Your father is lord Shiva. I give you the status of a god; the eternal chieftainship of the Gaṇas. Choose boons as you please. I am delighted. I shall grant you boons. You need not hesitate at all.”
He gave him the Pashupata rite, the Pashupata knowledge and the perpetual ability to propound and discourse. Obtaining the divine boons and the perpetual bachelorhood from Shiva & Parvati he became joyous. The brahmin then requested lord Shiva for a boon: - “O lord of the chiefs of the gods, be pleased. Please grant me devotion to you, great, divine and unflinching. Grant me an abiding faith in persons devoted to you. Grant me the great slavery and the perpetual proximity to you.”
Shiva said: — “O dear Upamanyu, I am delighted. Indeed, everything has been granted by me to you. O brahminical sage, you are of steady devotion. I wanted to test you. Be free from old age, death and misery. Be glorious and endowed with splendour and divine knowledge. Your kinsmen, your family and spiritual lineage shall be everlasting. O excellent brahmin, your devotion to me shall be permanent.”
Thus, granting him the boons lord Shiva who had the lustre of a crore suns, vanished there itself.