Matsya Purana — Phala-Saptamī Vow
प्रतिमासं च सप्तम्याम् एकैकं नाम कीर्तयेत् प्रतिपक्षं फलत्यागम् एतत्कुर्वन्समाचरेत् //
pratimāsaṃ ca saptamyām ekaikaṃ nāma kīrtayet pratipakṣaṃ phalatyāgam etatkurvansamācaret //
On the seventh day of each month, one should recite aloud a single sacred Name each time; and every fortnight one should renounce the fruits of one’s actions. Practising thus, one should duly observe the vow.
This verse is not about Pralaya; it teaches a practical discipline of devotion (name-recitation) and renunciation (giving up fruits of action) as part of regular vrata-observance.
It prescribes a steady routine compatible with worldly life: periodic nāma-kīrtana and the ethical practice of phala-tyāga, encouraging duty performed without attachment—ideal for householders and rulers alike.
The significance is ritual and calendrical: it specifies observance on saptamī (monthly) and a fortnightly discipline of renouncing rewards, forming part of a regulated vow rather than Vāstu or temple-construction rules.