Narada Purana — Purva Bhaga, Shloka 20
Tithi-Nirṇaya for Vratas: Ekādaśī Rules, Saṅkrānti Punya-kāla, Eclipse Observances, and Prāyaścitta
स्नानदानजपादीनां कुर्वतामक्षय फलम् । तत्र कर्कटको ज्ञेयो दक्षिणायनसंक्रमः ॥ २० ॥
snānadānajapādīnāṃ kurvatāmakṣaya phalam | tatra karkaṭako jñeyo dakṣiṇāyanasaṃkramaḥ || 20 ||
对行沐浴净身、布施（dāna）、持诵（japa）等诸仪轨者，其果报成为不灭不坏。于此当知：太阳入“迦尔迦塔迦”（Karkaṭaka，巨蟹）之时，即为达克希那耶那·桑克兰提（Dakṣiṇāyana-saṅkrānti），亦即太阳转入南行之际。
Sanatkumara (in dialogue with Narada)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: bhakti
FAQs
It teaches that performing core dharmic acts—snāna, dāna, and japa—at the Dakṣiṇāyana transition yields akṣaya (inexhaustible) merit, highlighting saṃkrānti as a spiritually potent time.
While framed as ritual timing, the verse supports bhakti in practice by directing devotees to intensify japa and charity on sacred calendrical thresholds, making devotion steady and fruitful.
Jyotiṣa (Vedāṅga astrology/astronomy): it identifies Dakṣiṇāyana-saṃkrānti specifically with the Sun’s ingress into Karkaṭa (Cancer), linking calendrical astronomy to ritual efficacy.