Matsya Purana — Ravi-Saṅkrānti Vow: Udyāpana
ततस्तु कर्मक्षयमाप्य सप्तद्वीपाधिपः स्यात्कुलशीलयुक्तः सृष्टेर्मुखे ऽव्यङ्गवपुः सभार्यः प्रभूतपुत्रान्वयवन्दिताङ्घ्रिः //
tatastu karmakṣayamāpya saptadvīpādhipaḥ syātkulaśīlayuktaḥ sṛṣṭermukhe 'vyaṅgavapuḥ sabhāryaḥ prabhūtaputrānvayavanditāṅghriḥ //
Then, when the residue of former karmic consequences has been exhausted, he becomes the lord of the seven continents—endowed with noble lineage and good conduct. At the dawn of creation he is born with an unblemished body, together with a wife, and his feet are revered by a great line of descendants and many sons.
It points to the post-cycle renewal of order: at the dawn of creation (sṛṣṭer mukhe), an ideal ruler arises once karmic residues are exhausted, indicating continuity of moral causality across cosmic cycles rather than describing the flood directly.
It frames kingship as the fruit of purified karma and emphasizes qualifications—kula (noble responsibility), śīla (ethical conduct), marital stability (sabhārya), and sustaining a righteous lineage—core ideals for a ruler and, by extension, a householder.
No direct Vāstu/temple rule is stated; the closest ritual note is the honor (vandita) shown to the ruler’s feet by descendants, reflecting a culture of ancestral/lineage reverence rather than architectural prescription.