Srimad Bhagvata Mahapurana: Book 10: Chapter 88: Verses 13-25
In order to illustrate this truth, the wise relate an ancient anecdote showing how by conferring a boon on the demon Vrka Lord Siva (who has His abode on Mount Kailasa) got into trouble. (Pariksit!) meeting (the celestial sage) Narada on the way, this evil-minded demon, Vrka by name, son of Sakuni, inquired (of him) which of the three gods (Brahma, Visnu and Siva) was quick to propitiate. The sage replied, " Betake yourself to Lord Siva. You will (thereby) gain your object very soon; He it is who is soon Pleased with a small measure of merit and gets angry equally quickly through a slight offence. pleased with Ravana (the ten-headed monster) and Bana (the demon), who (simply) glorified Him like bards, He conferred (on them) immense wealth and power, and courted serious trouble thereby (in that Ravana uprooted His very home, Mount Kailasa,
while Bana secured from Him a boon that He should ever guard his city)." _Instructed thus (by Narada), the demon worshipped Lord Siva (the Destroyer of the universe), propitiating Him by means of (oblations of) his own flesh out of his body through the mouth of fire at the sacred spot of)Kedara (a summit of the Himalayas). Unable to gain the sight of the Lord (even after worshipping Him in this way for six days) he proceeded out of despair, on the seventh day, to lop off with his sword his (very) head, the hair on which were wetted through a dip in the holy waters of that place, (and offer it as an oblation to Lord Siva). (O King !) the highly merciful Lord Siva (who wears matted locks on His head) rose out of the flames, (brilliant) like the god of fire, and, holding Vrka by the arms with His own, deterred the latter (from that terrible act) even as we would deter a friend from committing suicide. Through His blessed touch the demon was whole again.