Matsya Purana — Yadu Lineage
एवमुक्तो ऽब्रवीद्देवो व्रतं त्वं चर भार्गव पूर्णं वर्षसहस्रं तु कणधूममवाक्शिराः यदि पास्यसि भद्रं ते ततो मन्त्रानवाप्स्यसि //
evamukto 'bravīddevo vrataṃ tvaṃ cara bhārgava pūrṇaṃ varṣasahasraṃ tu kaṇadhūmamavākśirāḥ yadi pāsyasi bhadraṃ te tato mantrānavāpsyasi //
Thus addressed, the Lord said: “O Bhārgava, undertake this vow. For a full thousand years, drink only the smoke of chaff, keeping your head bowed downward. If you can observe it, blessings to you—then you shall obtain the mantras.”
This verse does not describe Pralaya; it focuses on tapas (austerity) and the disciplined observance of a vow as the means to attain mantras.
It highlights the Purāṇic ethic that spiritual attainments (like mantra-knowledge) arise from sustained self-control and vrata-observance—principles applicable to kings and householders as disciplined dharma, even if the specific austerity is ascetic.
The significance is ritual rather than architectural: it prescribes a severe vrata (time span, posture, and restricted intake) as a formal procedure leading to mantra-attainment (mantra-siddhi).