Chapter 35 of 42 · Shata Rudra Samhita · Overall chapter 264 of 464
Avatara as a Virtuous Brahmana
Anxious that Himalaya's devotion to Shiva through the marriage will earn him premature emancipation, the gods try repeatedly to find someone willing to discourage the match, and finally persuade Shiva to discourage it himself - which he does, disguised as a brahmana named Sadhudvija, by delivering an extended, deliberately self-deprecating list of his own flaws to Himalaya in person.
Nandishvara said
Sanatkumara, hear of the lord Shiva's avatara as a virtuous brahmana. All the gods learned of the great and supreme devotion Mena and Himalaya had developed toward Shiva, and, full of thought, consulted each other affectionately. They said: if, in single-minded devotion, the lord of mountains gives his daughter to Shambhu, he will surely gain nirvana, at once obtain Shiva, and, though he is a store of countless jewels, gain moksha. This earth is known as having a womb full of jewels, but that will then become false. He will give up his present transient form and take a divine one, and, giving his daughter to the trident-wielder, go to Shiva's world, gain likeness to Mahadeva by Shambhu's favour, enjoy fine pleasures there and obtain liberation. Discussing this, all the gods went to their guru's house, and, intent on their own ends, said: guru, to accomplish our task please go to Himalaya's house and criticise Mahesha so that the mountain's devotion to him is checked; if the mountain gives his daughter to Shiva while full of his devotion he will at once gain liberation, so let him stay on earth. Hearing them, he reflected and said that one of them should go to the mountain, for he could not do it; or they should go with Vasava to Brahma's world and tell him, and he would accomplish their task. Hearing this, the gods discussed and went to Brahma's assembly hall and reported everything to him. Hearing them Brahma thought long and said he could not do this, since criticising Hara always brings grief. They should go to Kailasa and satisfy Shankara, asking the divinity to go to Himalaya's house himself and criticise himself, for it is held that criticising others leads to destruction but criticising oneself leads to fame. So all the gods quickly went to Kailasa, bowed devotedly to Shiva and told him everything. Hearing them, Maheshvara agreed, and, smiling, comforted and assured the gods.
Bhagavan Shambhu Mahesha, kind to devotees, faultless and lord of maya, wished to go to the mountain. He took a staff and an umbrella and dressed in divine garments, radiant with a dazzling tilaka, a string of crystal beads in his hand and a shalagrama round his neck, devotedly doing japa of Hari's name, in the garb of a virtuous brahmana. Surrounded by his relatives he quickly went to Himachala. Seeing him with his attendants Himalaya stood, and, by the rules, lay on the ground like a rod. The lord of mountains asked who he was. With fitting affection the foremost brahmana replied at once: mountain, I am known as Sadhudvija and also as Vishnu's devotee. I have supreme insight, know everything and always do good to others. By my guru's strength I can go anywhere. Supreme among mountains, by my own knowledge, while in my own abode, I came to know something. Listen lovingly: I will tell it without any pride in your presence. You wish to give your daughter to Shankara. She is lovely as Padma, but his lineage and conduct are unknown. Lord of mountains, this decision of yours is not fitting and will lead to nothing auspicious. Born in Narayana's line you are foremost among those with knowledge and must understand. Look at your kingdom over the mountains. He does not have a single relative. Make the effort to ask your own relatives and your beloved, ask everyone, including Mena, but leave out Parvati. Mountain, a sick person does not like medicine and prefers a bad diet. He is not a worthy person for the rite of giving away Parvati. As soon as they hear of it, great people will smile. He is without refuge and always without attachment, malformed, unchanging and without gunas, hideous, living in cremation grounds, fond of serpents, naked, with ashes for ornaments and snakes coiled round his head. He has been cast out from all the ashramas and his movements can never be known. Having uttered these factual statements, full of criticisms of Shiva, Shiva, who engages in play, returned to his own abode. Hearing the brahmana, the two took contrary meanings from his words and wondered what to do. Then Rudra brought great joy to his devotees, married Girija and accomplished the gods' task. Nandi said he had told of Shiva's avatara called Sadhudvija, by which the lord accomplished the gods' task. This unsullied account ensures heaven and a long, excellent life, and one who reads or hears it gains a happy destination.
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.