Matsya Purana — Measures of Time: Caturyuga Computation, Shloka 2
*सूत उवाच पृथिवीद्युप्रसङ्गेन मया तु प्रागुदाहृतम् एतच्चतुर्युगं त्वेवं तद्वक्ष्यामि निबोधत तत्प्रमाणं प्रसंख्याय विस्तराच्चैव कृत्स्नशः //
*sūta uvāca pṛthivīdyuprasaṅgena mayā tu prāgudāhṛtam etaccaturyugaṃ tvevaṃ tadvakṣyāmi nibodhata tatpramāṇaṃ prasaṃkhyāya vistarāccaiva kṛtsnaśaḥ //
スータは言った。「以前、地と天界の話の折に、すでにそれを述べた。今ここに、このチャトゥルユガ（四時代の循環）を汝らに説き明かそう。正しい数え上げにより、その尺度を余すところなく、しかも詳しく示すゆえ、心して聞け。」
FAQs
It does not describe pralaya directly; it introduces a systematic explanation of cosmic time (the caturyuga), which is the chronological framework within which creation, preservation, and dissolution narratives are timed.
By announcing the yuga framework, it implies that dharma and social duties are understood relative to time: royal policy and household conduct are traditionally adjusted according to the moral and spiritual conditions of each yuga.
No specific vastu or ritual rule appears in this verse; its practical significance is foundational—ritual calendars, donations, and observances in Purāṇic tradition are often contextualized within yuga-based chronology.