Matsya Purana — Vrata-Ṣaṣṭhī: The Sixty Sacred Vows
गौरीलोके वसेत्कल्पं ततो राजा भवेदिह एतद्रुद्रव्रतं नाम सदा कल्याणकारकम् //
gaurīloke vasetkalpaṃ tato rājā bhavediha etadrudravrataṃ nāma sadā kalyāṇakārakam //
He dwells for a kalpa in Gaurī’s realm; thereafter, here (on earth) he becomes a king. This observance is called the Rudra-vrata, and it is ever a cause of auspicious welfare.
This verse does not address pralaya; it focuses on the fruit (phala) of a Śaiva observance—attaining Gaurī’s realm for a kalpa and later gaining kingship on earth.
It presents vrata-practice as a dharmic means by which a householder may gain both otherworldly merit (residence in a divine realm) and worldly legitimacy/prosperity (becoming a king), aligning royal fortune with ritual discipline.
The significance is ritual, not architectural: it is a phala-śruti for the Rudra-vrata, stating its auspicious, welfare-producing power and its promised results.