Narada Purana — Purva Bhaga, Shloka 26
Tithi-Nirṇaya for Vratas: Ekādaśī Rules, Saṅkrānti Punya-kāla, Eclipse Observances, and Prāyaścitta
स्नात्वा भुंजीत विप्रेंद्र परेद्युः शुद्धमंडलम् । दृष्टचंद्रा सिनीवाली नष्टचंद्रा कुहूः स्मृता ॥ २६ ॥
snātvā bhuṃjīta vipreṃdra paredyuḥ śuddhamaṃḍalam | dṛṣṭacaṃdrā sinīvālī naṣṭacaṃdrā kuhūḥ smṛtā || 26 ||
噢婆罗门中之最胜者，沐浴之后，当于次日月轮清净之时进食。见月之日，称为“西尼瓦利”（Sinīvālī）；不见月之日，名为“库胡”（Kuhū）。
Sanatkumara (teaching Narada)
Vrata: Sinīvālī/Kuhū observance context (tithi-day identification; vrata not explicitly named)
Primary Rasa: shanta
Secondary Rasa: bhakti
FAQs
It links ritual purity and disciplined eating to correct lunar timing, teaching that dharmic practice should follow the lunar calendar (tithi) as defined by the Moon’s visibility.
By emphasizing orderly vrata conduct—bathing, restraint, and proper timing—it supports sattva and steadiness, which are foundational disciplines that sustain Vishnu-bhakti and regular worship.
Vedāṅga Jyotiṣa: identifying specific lunar days (Sinīvālī and Kuhū) through whether the Moon is visible, guiding ritual scheduling and vrata observance.