Śiva is the lord of worlds, the mobile and immobile beings. He is the lord of heaven. He can do everything. He is the bestower of worldly pleasures and salvation.
Now onwards leave that mantra and worship Śiva with devotion through the rules laid down for the worship of his day phallic image and by contemplating on him.
O Bhārata, by your devotional feelings and modes of service, you worship Śiva. Your achievement will be unshakable. No doubt need be entertained in this respect.