Adhyaya 52: सोमाधारः, पुण्योदानदी, मेरुप्रदक्षिणा, जम्बूद्वीपनववर्षवर्णनम्
वर्षाणां तत्र जीवन्ति अश्वत्थाशनजीवनाः हैरण्मया इवात्यर्थम् ईश्वरार्पितमानसाः
varṣāṇāṃ tatra jīvanti aśvatthāśanajīvanāḥ hairaṇmayā ivātyartham īśvarārpitamānasāḥ
そこで彼らは幾年も生き、聖なるアシュヴァッタ(aśvattha)の葉を食として身を支える。黄金のごとく輝き、全身全霊で没入し—心をイーシュヴァラ(シヴァ)に捧げる。束縛されたパシュ(paśu)をパーシャ(pāśa)より解き放つ主、パティである。
Suta Goswami
It emphasizes inner offering (mānasa-arpana): true devotion to the Lord behind the Linga is shown by a mind surrendered to Īśvara, supported by purity and restraint.
Shiva is implied as Īśvara/Pati—the sovereign Lord to whom the devotees dedicate their consciousness, and by whose grace the bound soul (paśu) can become purified and radiant.
A tapas-oriented, Pāśupata-style discipline: austerity, simple sustenance (aśvattha-based), and continuous mental dedication to Īśvara.