Srimad Bhagvata Mahapurana: Book 10: Chapter 88: Verses 26-40
It is the realm of Bhagavan Narayana, the supreme resort of recluses who, having taken a vow of complete non-violence have attained perfect tranquillity of mind. On reaching this region one does not return to mundane life. Seeing Siva in that miserable plight, from a distance, Bhagavan Narayana, who removes all affliction, assumed the form of a young Brahmacari (religious student) by dint of His Yogamaya (wonderful creative power) and appeared before Vrkasura. Adorned with a girdle made of Munja grass, (black) deer-skin, a staff and a rosary of Rudraksa beads, He shone by His lustre like the fire. Holding a (bunch of) Kusa grass in His hand, He hailed the Asura like a humble student. The Lord (disguised as a Brahmacari) said : 0 Vrkasura, evidently you are (much) fatigued. Have you covered a long distance? Rest Yourself awhile. This body is the source of all blessings. (Why do you put it to unnecessary exertion ?) Mighty as you are, please tell me, if the matter is fit for our ears, what you have set your mind upon. For people generally seek to accomplish their object through persons choosen for their help. Sri Suka went on : (Pariksit !) thus questioned by the Lord in words raining nectar (as it were) the Asura felt refreshed and related to Him in order of sequence all that he had done. The Lord said : "If it is so, then we do not believe his words. Do you not know that under the curse of Daksa He has adopted the ways of Pisacas (evil spirits)? He is now the ruler of Pretas (genii) and Pisacas.
0 lord of demons, if you still repose faith in Sankara as the Teacher of the world, the truth may be verified (by you) this very instant, ,O dear friend, by placing your hand on your own head. O chief of Asuras, if the words of Sankara are found to deviate from truth in any wise, you had better do away with that liar so that he may not (live to) utter a falsehood again." The words spoken by the Lord were so very sweet and cast such a magic spell on him that he lost his reasoning power, and the wicked Asura in utter forgetfulness placed his hand on his own head. Instantaneously he fell down with his head split as if by a stroke of lightning; and shouts of triumph, salutations and applause were raised (by the gods) in heaven. On the sinful Vrkasura rained having been killed, gods, manes and Gandharvas showers of flowers, and Bhagavan Sankara was redeemed from a precarious situation. The almighty Lord Visnu (thereupon) said to Sankara, who was (now) free, " 0 Lord ! 0 supreme Deity, this wicked Asura has been killed by his own sins. 0 Lord, having actually sinned against the great who can possibly be happy? Much less could he be happy who did wrong to You the Lord and preceptor of the universe". Sri Hari is an ocean of powers, which are both incomprehensible and beyond the range of speech. He is no other than the Supreme Spirit beyond Prakrti. He who relates or listens to this story of His rescuing Lord Sankara (from trouble) gets completely freed from(the cycle of) births and deaths and is rid of the fear of enemies.
Thus ends the eighty-eighth discourse entitled "Lord Rudra rescued (from trouble),"
in the latter half of Book Ten of the great and glorious Bhagavata-Purana, otherwise known as the Paramahamsa-Samhita.