Matsya Purana — Division of Bhārata-varṣa
चत्वारि भारते वर्षे युगानि मुनयो ऽब्रुवन् कृतं त्रेता द्वापरं च कलिश्चेति चतुर्युगम् तेषां निसर्गं वक्ष्यामि उपरिष्टाच्च कृत्स्नशः //
catvāri bhārate varṣe yugāni munayo 'bruvan kṛtaṃ tretā dvāparaṃ ca kaliśceti caturyugam teṣāṃ nisargaṃ vakṣyāmi upariṣṭācca kṛtsnaśaḥ //
The sages declare that, in Bhārata-varṣa, there are four ages—Kṛta, Tretā, Dvāpara, and Kali—together forming the cycle of four yugas (caturyuga). I shall explain their succession and full arrangement in due order hereafter.
This verse does not describe pralaya directly; it introduces the framework of cosmic time (the four yugas) that governs how the world’s order unfolds, within which creation, decline, and eventual dissolution are later understood.
By defining the yugas, the text prepares the ethical context: dharma and social duties are traditionally taught as varying in strength across Kṛta, Tretā, Dvāpara, and Kali, guiding kings and householders to uphold righteousness appropriate to their age.
No specific Vāstu or ritual procedure is stated here; the verse serves as a cosmological preface, which later chapters may connect to age-based changes in ritual practice and religious norms.