Adhyaya 70: आदिसर्गः—महत्-अहङ्कार-तन्मात्रा-भूतसृष्टिः, ब्रह्माण्डावरणम्, प्रजासर्गः, त्रिमूर्ति-शैवाधिष्ठानम्
त्रिधा यद्वर्तते लोके तस्मात्त्रिगुण उच्यते चतुर्धा प्रविभक्तत्वाच् चतुर्व्यूहः प्रकीर्तितः
tridhā yadvartate loke tasmāttriguṇa ucyate caturdhā pravibhaktatvāc caturvyūhaḥ prakīrtitaḥ
Weil es in der Welt in drei Weisen wirkt, wird es daher «mit den drei Guṇas begabt» (triguṇa) genannt. Und weil es vierfach gegliedert ist, wird es als «vierfache Manifestation» (caturvyūha) verkündet.
Suta Goswami (narrating the doctrine as received in the Purana’s teaching lineage)
It frames the cosmos encountered in Linga-pūjā as guṇa-governed (threefold), while pointing to a higher Shaiva principle that also expresses itself in a fourfold order—helping the worshipper discern the manifested world from Shiva (Pati) who is ultimately beyond guṇas.
It implies a distinction: worldly functioning is triguṇic (prakṛti and its effects), yet the supreme Shaiva reality can be spoken of as arranging manifestation in a fourfold way; in Shaiva Siddhanta, Shiva as Pati is not limited by guṇas even while governing their play for the sake of sṛṣṭi and anugraha (grace).
The takeaway for Pāśupata-oriented sādhana is guṇa-śuddhi: observing and transcending sattva–rajas–tamas through discipline, mantra, and Linga-upāsanā, so the Pashu (soul) loosens pāśa (bondage) and turns toward Pati (Shiva).