वासिष्ठकथनम् (आदित्य–सोमवंशवर्णनम् तथा रुद्रसहस्रनाम-प्रशंसा)
रत्नभूतो ऽथ रत्नाङ्गो महार्णवनिपातवित् मूलं विशालो ह्यमृतं व्यक्ताव्यक्तस्तपोनिधिः
ratnabhūto 'tha ratnāṅgo mahārṇavanipātavit mūlaṃ viśālo hyamṛtaṃ vyaktāvyaktastaponidhiḥ
He is the very essence of jewels, His limbs radiant like gems; the Knower of the descent into the great cosmic ocean. He is the Root-cause, the Vast One; the Deathless Nectar, Amṛta itself. He is both manifest and unmanifest; the treasure-house of tapas—such is that Pati, Lord Śiva.
Suta Goswami (narrating the Shiva Sahasranama within the Linga Purana to the sages of Naimisharanya)
It frames the Linga as the mūla (root-cause) and amṛta (immortality) itself—guiding the devotee to worship not merely a symbol, but Pati (Śiva) who pervades both the visible and invisible.
Śiva is presented as vyakta-avyakta—simultaneously manifest in form and unmanifest beyond form—while remaining viśāla (all-pervading), the deathless ground of all beings (Pashus) and their liberation from Pāśa (bondage).
The epithet taponidhiḥ emphasizes tapas and disciplined Pāśupata-oriented sādhanā: sustained austerity, mantra-japa, and contemplative absorption on the Linga as the vast, deathless Reality.