Matsya Purana — Navagraha Sacrifice for Planetary Pacification and Prosperity
विद्वेषणे ऽभिचारे च त्रिकोणं कुण्डमिष्यते द्विमेखलं कोणमुखं हस्तमात्रं च सर्वशः //
vidveṣaṇe 'bhicāre ca trikoṇaṃ kuṇḍamiṣyate dvimekhalaṃ koṇamukhaṃ hastamātraṃ ca sarvaśaḥ //
For rites meant to cause enmity (vidveṣaṇa) and for acts of sorcery (abhicāra), a triangular fire-pit (kuṇḍa) is prescribed. It should have two surrounding girdles (dvimekhala), an angular mouth (koṇamukha), and be one cubit in measure on all sides.
Nothing directly—this verse is technical Vastu/ritual instruction about the geometry and measurement of a homa fire-pit for specific rites, not about cosmic creation or Pralaya.
It frames a rule-based ritual technology: a king (or patron) is expected to follow prescribed procedures and measurements when commissioning rites; the verse specifies the correct kunda-shape for particular intentions (vidveṣaṇa/abhicāra), emphasizing precision in ritual performance.
It gives kunda-lakṣaṇa: for vidveṣaṇa and abhicāra rites the fire-pit should be triangular, with two encircling bands (dvimekhala), an angular mouth (koṇamukha), and a standard one-hasta measure on all sides.