Adhyaya 45: Rudra as Sarvatma—Seven Lokas, Seven Talas, and the Cosmic Body of Shiva
अनेन निर्मितास्त्वेवं तदात्मानो द्विजर्षभाः समष्टिरूपः सर्वात्मा संस्थितः सर्वदा शिवः
anena nirmitāstvevaṃ tadātmāno dvijarṣabhāḥ samaṣṭirūpaḥ sarvātmā saṃsthitaḥ sarvadā śivaḥ
Thus, O best of the twice-born, by Him all these were fashioned as expressions of His own being. Shiva—ever established as the Self of all—abides perpetually in the universal, collective form (samaṣṭi-rūpa).
Suta Goswami (narrating to the sages at Naimisharanya)
It grounds Linga worship in metaphysics: the Linga signifies Shiva as the ever-present Sarvātman, the collective ground (samaṣṭi) from which all forms arise and in which all abide.
Shiva is presented as Pati—the abiding Lord who is simultaneously transcendent creator and immanent Self of all (sarvātmā), with the universe as His own expression (tad-ātmānaḥ).
The key takeaway is contemplative upāsanā: in puja and Pāśupata-oriented meditation, one should recognize all beings (paśu) as pervaded by Shiva, loosening pāśa (bondage) through insight into His sarvātmatva.