Matsya Purana — Manvantaras
कर्णकश्च ऋषिः सिद्धस् तथा पूर्वातिथिश्च यः //
karṇakaśca ṛṣiḥ siddhas tathā pūrvātithiśca yaḥ //
Also (there are) the seer Karṇaka, the perfected one Siddha, and likewise the one named Pūrvātithi.
This verse does not describe Pralaya; it functions as a catalogue line naming revered beings (a ṛṣi and siddha figures) preserved in the Purana’s tradition.
Indirectly, such name-lists anchor dharma through lineage and authority: kings and householders are encouraged to honor sages, learn from their teachings, and uphold rites and ethical conduct validated by these traditional transmitters.
No explicit Vāstu/temple rule is stated here; the ritual takeaway is reverence for ṛṣis and siddhas, whose remembered names often accompany recitation, lineage-invocation, and Purāṇic transmission.