Narada Purana — Purva Bhaga, Shloka 54
Tithi-Nirṇaya for Vratas: Ekādaśī Rules, Saṅkrānti Punya-kāla, Eclipse Observances, and Prāyaścitta
उपोष्या द्वादशी शुद्धा सर्वैरेव न संशयः । केचिदाहुश्च पूर्वां तु तन्मतं न समंजसम् ॥ ५४ ॥
upoṣyā dvādaśī śuddhā sarvaireva na saṃśayaḥ | kecidāhuśca pūrvāṃ tu tanmataṃ na samaṃjasam || 54 ||
The pure Dvādaśī day is indeed to be observed as the fasting day—about this there is no doubt among all authorities. Some, however, say it should be the earlier day; but that opinion is not consistent.
Sage Narada (teaching in a vrata/ritual context)
Vrata: Ekadashi (contextual; Dvādaśī fasting rule)
Primary Rasa: shanta
Secondary Rasa: vira
FAQs
It stresses correct observance of the Vaiṣṇava vow by insisting on śuddha Dvādaśī for fasting, implying that dharma is protected by precise adherence to proper tithi.
By prioritizing the properly determined Dvādaśī fast, it frames devotion as disciplined worship—bhakti expressed through accurate vrata practice rather than personal preference.
It reflects calendrical/tithi determination used in ritual decision-making (a practical application aligned with Jyotiṣa-style timekeeping for vrata observance).