Srimad-Bhagavatam: Canto 8 - Chapter 1 - Verse 4
श्रीमहादेव उवाचदेवदेव जगद्वयापिञ्जगदीश जगन्मय ।सर्वेषामपि भावानां त्वमात्मा हेतुरीश्वर: ॥ ४ ॥
śrī-mahādeva uvācadeva-deva jagad-vyāpiñjagad-īśa jagan-mayasarveṣām api bhāvānāṁtvam ātmā hetur īśvaraḥ
Lord Mahādeva said: O chief demigod among the demigods, O all-pervading Lord, master of the universe, by Your energy You are transformed into the creation. You are the root and efficient cause of everything. You are not material. Indeed, You are the Supersoul or supreme living force of everything. Therefore, You are Parameśvara, the supreme controller of all controllers.
The Supreme Personality of Godhead, Viṣṇu, resides within the material world as the sattva-guṇa-avatāra. Lord Śiva is the tamo-guṇa-avatāra, and Lord Brahmā is the rajo-guṇa-avatāra, but although Lord Viṣṇu is among them, He is not in the same category. Lord Viṣṇu is deva-deva, the chief of all the demigods. Since Lord Śiva is in this material world, the energy of the Supreme Lord, Viṣṇu, includes Lord Śiva. Lord Viṣṇu is therefore called jagad-vyāpī, “the all-pervading Lord.” Lord Śiva is sometimes called Maheśvara, and so people think that Lord Śiva is everything. But here Lord Śiva addresses Lord Viṣṇu as Jagadīśa, “the master of the universe.” Lord Śiva is sometimes called Viśveśvara, but here he addresses Lord Viṣṇu as Jaganmaya, indicating that even Viśveśvara is under Lord Viṣṇu’s control. Lord Viṣṇu is the master of the spiritual world, yet He controls the material world also, as stated in Bhagavad-gītā (mayādhyakṣeṇa prakṛtiḥ sūyate sacarācaram). Lord Brahmā and Lord Śiva are also sometimes called īśvara, but the supreme īśvara is Lord Viṣṇu, Lord Kṛṣṇa. As stated in Brahma-saṁhitā, īśvaraḥ paramaḥ kṛṣṇaḥ: the Supreme Lord is Kṛṣṇa, Lord Viṣṇu. Everything in existence works in proper order because of Lord Viṣṇu. Aṇḍāntara-stha-paramāṇu-cayāntara-stham. Even paramāṇu, the small atoms, work because of Lord Viṣṇu’s presence within them.