अध्याय 91: अरिष्ट-लक्षण, मृत्यु-संस्कार, पाशुपत-धारणा तथा ओङ्कार-उपासना
अकारो ह्यक्षरो ज्ञेय उकारः सहितः स्मृतः मकारसहितौंकारस् त्रिमात्र इति संज्ञितः
akāro hyakṣaro jñeya ukāraḥ sahitaḥ smṛtaḥ makārasahitauṃkāras trimātra iti saṃjñitaḥ
「A」の字を根本の音節として知れ。これに「U」が結び合わされると伝えられ、さらに「M」を加えると「オーム(Oṃ)」の音が成る—ゆえにそれは三つのマートラー(trīmātrā)と名づけられる。
Suta Goswami (narrating the Linga Purana teaching on Pranava to the sages of Naimisharanya)
It grounds Linga-puja in the Pranava: Oṃ as the seed-sound of Pati (Shiva), showing that worship begins with mantra and culminates in inner recognition of the imperishable (akṣara) reality symbolized by the Linga.
By defining Oṃ as the imperishable akṣara composed of three mātrās, it points to Shiva-tattva as the transcendent Pati who is approached through sound (nāda) yet remains beyond letters—revealed through the unified Pranava.
Japa and upāsanā of Oṃ (auṃkāra), contemplated as A-U-M (trimātra), used in Shaiva/Pāśupata practice to purify the pashu (soul) from pāśa (bondage) and steady awareness in the Lord.