उमामहेश्वरव्रतं—पञ्चाक्षरमन्त्रस्य माहात्म्यं, न्यासः, जपविधिः, सदाचारः, विनियोगः
षडङ्गानि न्यसेत्पश्चाद् यथास्थानं च शोभनम् नमः स्वाहा वषड्ढुं च वौषट्फट्कारकैः सह
ṣaḍaṅgāni nyasetpaścād yathāsthānaṃ ca śobhanam namaḥ svāhā vaṣaḍḍhuṃ ca vauṣaṭphaṭkārakaiḥ saha
Thereafter, one should perform the placement (nyāsa) of the six mantra-limbs (ṣaḍaṅga) in their proper locations, in a fitting and auspicious manner—together with the ritual utterances: namaḥ, svāhā, vaṣaṭ, the hūṃ-bīja, vauṣaṭ, and phaṭ.
Suta Goswami (narrating Shiva-puja procedures to the sages of Naimisharanya)
It prescribes ṣaḍaṅga-nyāsa—placing the mantra’s six limbs on their proper loci—so the worshipper’s body and speech become ritually aligned for Linga-pūjā, establishing protection (rakṣā) and fitness (adhikāra) for approaching Pati (Shiva).
By emphasizing nyāsa and mantric limbs, it presents Shiva as Pati who is accessed through śabda (mantra) and śakti (ritual potency): the bound pashu approaches liberation by sanctifying the embodied field where pasha operates, turning it into a vessel of Shiva’s presence.
Ṣaḍaṅga-nyāsa with protective and offering utterances (namaḥ, svāhā, vaṣaṭ, hūṃ, vauṣaṭ, phaṭ), a core preparatory practice in Shaiva pūjā that also functions yogically as mantra-śuddhi and rakṣā before deeper Pashupata-oriented worship.