Narada Purana — Purva Bhaga, Shloka 4
Gṛhastha-praveśa: Vivāha-bheda, Ācāra-śauca, Śrāddha-kāla, and Vaiṣṇava-lakṣaṇa
मातृतः पंचमीं धीमान्पितृतः सप्तमीं तथा । द्विजः समुद्वहेत्कन्यथा गुरुतल्पराः ॥ ४ ॥
mātṛtaḥ paṃcamīṃ dhīmānpitṛtaḥ saptamīṃ tathā | dvijaḥ samudvahetkanyathā gurutalparāḥ || 4 ||
聪明的再生族（Dvija）应当娶母系五代以外、父系七代以外的女子为妻；否则，他将如玷污古鲁（Guru）之床者一般受谴责。
Narada (teaching Dharma in the Purva Bhaga context)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: bhayanaka
FAQs
It frames marriage as a Dharma-sacrament: maintaining purity of lineage and social order is treated as a serious spiritual duty, and violating kinship boundaries is equated with a grave moral fall.
By insisting on righteous conduct (ācāra) in household life, it supports Bhakti indirectly—devotion is strengthened when one’s life is aligned with Dharma and free from major transgressions.
It points to applied Dharma-śāstra practice: determining kinship degrees requires careful knowledge of lineage reckoning (genealogy used in ritual/legal contexts) to avoid sapinda-like prohibited unions.