Shiva's gift to ravana.

         Once Ravana requested Lord Shiva to visit Lanka but he refused to leave mount kailash. Ravana was obsessed of his victory and power. Though he lift the mount kailash. Lord Shiva got angry on his action. So he put a toe on kailash and it struck on ravana's fingers, he started screamings
                            Ravana realised  his mistake and strated to singing a song of his power and beauty. So he could calm down, ravara called him distroyer, distroyer of death itself.

                    Because of intensity of his     prayers Lord Shiva bless him with power and a sword called Chandrahas. The song sang by ravana is known as Shiv Tandav Stotram. Shiva's idol based on it.