Matsya Purana — Dynastic Genealogies: Paurava–Anu Lines
अवतारयामास महीं मन्त्रैर्वाहनमुत्तमम् हर्यङ्गस्य तु दायादो जातो भद्ररथः किल //
avatārayāmāsa mahīṃ mantrairvāhanamuttamam haryaṅgasya tu dāyādo jāto bhadrarathaḥ kila //
By sacred mantras he caused the excellent mount to descend upon the earth. And it is said that Bhadraratha was born as the heir of Haryaṅga.
This verse does not address Pralaya; it focuses on dynastic succession and a mantra-invoked descent/manifestation of an excellent “vehicle/mount.”
It reflects the Purāṇic emphasis on legitimate succession (dāyāda) and the kingly ideal of maintaining continuity of rule; it also implies reliance on mantra and ritual authority as part of royal culture.
The ritual element is the efficacy of mantras to “cause descent/manifestation” (avatāraṇa) of a revered object or vehicle—an idea aligned with consecratory and invocation rites, though no specific Vāstu or temple rule is stated in this verse.