उमामहेश्वरव्रतं—पञ्चाक्षरमन्त्रस्य माहात्म्यं, न्यासः, जपविधिः, सदाचारः, विनियोगः
अस्नात्वा न च भुञ्जीयाद् अजपो ऽग्निमपूज्य च पर्णपृष्ठे न भुञ्जीयाद् रात्रौ दीपं विना तथा
asnātvā na ca bhuñjīyād ajapo 'gnimapūjya ca parṇapṛṣṭhe na bhuñjīyād rātrau dīpaṃ vinā tathā
อย่ารับประทานโดยไม่อาบน้ำ; อย่ารับประทานโดยไม่สวดชปะ และโดยไม่บูชาไฟศักดิ์สิทธิ์ก่อน อย่ารับประทานบนภาชนะใบไม้; และอย่ารับประทานในยามราตรีโดยไม่มีประทีป
Suta Goswami (narrating Shaiva dharma instructions to the sages of Naimisharanya)
It frames eating as an extension of pūjā-discipline: bodily purity (snāna), mantra-remembrance (japa), and honoring Agni support a sattvic state suitable for Shiva-bhakti and Linga-sevā.
Indirectly, it points to Shiva as Pati—the Lord accessed through inner remembrance and outer order: japa aligns the pashu (soul) toward Shiva, while disciplined conduct reduces pasha (bondage) born of negligence and tamas.
Daily niyamas linked with Pashupata-leaning practice: snāna (śauca), japa (mantra-yoga), and Agni-upacāra before meals; also the rule of taking food with proper light at night.