Adhyaya 84: शिवव्रतकथनम्
Uma–Maheshvara Vrata, Shula-dana, and Month-wise Ekabhakta Vrata
पौर्णमास्याममावास्यां वर्षमेकमतन्द्रिता उपवासरता नारी नरो ऽपि द्विजसत्तमाः
paurṇamāsyāmamāvāsyāṃ varṣamekamatandritā upavāsaratā nārī naro 'pi dvijasattamāḥ
ಹೇ ದ್ವಿಜಸತ್ತಮರೇ, ಪೂರ್ಣಿಮೆ ಮತ್ತು ಅಮಾವಾಸ್ಯೆಯಂದು ಒಂದು ವರ್ಷ ಕಾಲ ಯಾವ ಸ್ತ್ರೀ—ಹಾಗೆಯೇ ಪುರುಷನೂ—ಅಲಸ್ಯವಿಲ್ಲದೆ ಉಪವಾಸದಲ್ಲಿ ನಿರತನಾಗಿರುತ್ತಾನೋ/ಇರುತ್ತಾಳೋ.
Suta Goswami
It prescribes a year-long discipline of fasting on Pūrṇimā and Amāvāsyā as a purificatory vrata that supports Śiva-pūjā and ripens the devotee for Śiva’s anugraha (grace).
Śiva is implied as Pati—the liberating Lord—whose grace is approached through steadiness (atandritā) and self-restraint, weakening pāśa (bondage) that constrains the paśu (individual soul).
Upavāsa as a vrata: periodic fasting on lunar junctions (full and new moon) for a year, a tapas-oriented practice aligned with Shaiva observance and preparatory to deeper Pāśupata discipline.