Chapter 36 of 76 · Vayaviya Samhita · Overall chapter 424 of 464
Krishna Obtains a Son
Resuming after a recess, Vayu opens the Uttara Bhaga by explaining how Krishna himself, late in his avatara, sought out the now-grown Upamanyu, received the panchakshara teaching and a twelve-month Pashupata vrata from him, and in turn obtained a son - Samba - directly from Shiva and Devi as the fruit of his resulting austerities.
Vayu said
I bow to the cause of the whirling of all samsara, whose chest bears the saffron stains from Gouri's two breasts.
Suta said
The sun had reached the midpoint of the sky. After telling how Upamanyu won Bhagavan's favour, Vayu rose to do his rites. All the sages of Naimisharanya consulted each other and settled what to ask next. As before, having done their own daily rites, they saw the illustrious one returning and sat down. After finishing his niyamas, the illustrious one born of the sky came, and took a fine seat among the sages. Vayu, worshipped by the worlds, sat at ease. Holding in his heart the glorious prosperity of Isha, he said, "I take refuge in Mahadeva, the all-knowing, the unconquered. The whole universe with its moving and unmoving things is his glory." Hearing these auspicious words, the rishis, whose sins were destroyed, wanted to hear about that glory in detail and spoke.
The rishis said
Illustrious one, you have already told the account of the great-souled Upamanyu, who did austerities for milk and received it from Parameshvara. We have heard that Vasudeva Krishna, faultless in deeds, went to Dhoumya's elder brother, kept the Pashupata vrata and gained supreme knowledge. How did Krishna gain that supreme knowledge of Pashupata?
Vayu answered
Of his own will the eternal Vasudeva took an avatara. Since the human condition is looked down on, he purified his body. For the sake of a son he tormented himself with austerities. He went to the great sage's hermitage to see him, and saw the sage there with ash smeared on all his limbs, a Tripundra mark on his forehead, a garland of rudraksha beads, and a crown of matted hair. He was surrounded by sages who were his disciples, as the Vedas are surrounded by the sacred texts, and he was absorbed in meditation on Shiva.
The serene Upamanyu was brilliant. Seeing him, Krishna was delighted and the hair stood on his body. He bowed, circled him three times with great respect, and with lowered shoulders and joined hands praised him. As soon as the wise Krishna saw the sage, all the impurities that came from maya and karma were destroyed. With the impurities gone, Upamanyu by the rules recited "Agni is this ash" and other mantras and smeared Krishna's body with ash. The sage taught him the excellent knowledge of how to keep a Pashupata vrata of twelve months. Since then Krishna has always been surrounded by sages firm in their vows, divine ones who are Pashupatas. Urged by his guru, the mighty Krishna did austerities to Shankara and Amba to gain a son. At the end of a year Parameshvara appeared. Shiva, with great prosperity, came with Amba and his ganas, taking this auspicious form to give a boon. Krishna bowed, joined his hands properly and praised him. His mind pleased with the austerities, Shiva, with Amba and the chief ganas, gave Vishnu a son. Since Mahadeva gave him this son together with Amba, Jambavati's son was named Samba. So I have told you everything about Krishna, whose deeds were endless: he gained knowledge from the great sage and a son from Shankara. A person who recites this constantly, or has it heard, gains knowledge of Vishnu and rejoices with him.
Retold in our own words from Bibek Debroy's English translation of the Shiva Purana (Penguin Classics). Names, numbers and the order of events follow the source.