Matsya Purana — Manvantaras
अत्र वो वर्णयिष्यामि विधिं मन्वन्तरस्य तु तथैव चातुर्होत्रस्य चातुर्वर्ण्यस्य चैव हि //
atra vo varṇayiṣyāmi vidhiṃ manvantarasya tu tathaiva cāturhotrasya cāturvarṇyasya caiva hi //
Here I shall describe to you the proper procedure (vidhi) concerning the Manvantara, and likewise the four-priest sacrificial system (cāturhotra), and also the order and duties of the four social classes (cāturvarṇya).
This verse does not describe Pralaya directly; it signals a shift into structured teaching on cosmic time (Manvantara-epochs) and the dharmic systems that operate within them.
By introducing cāturvarṇya and ritual order, the verse frames social duty: kings uphold varṇa-based governance and protection of dharma, while householders sustain sacrifice and social stability through prescribed rites.
The ritual significance is explicit: cāturhotra refers to the four-priest framework essential to Vedic yajña performance, indicating an upcoming procedural exposition rather than temple architecture (vāstu) details.