Matsya Purana — Navagraha Sacrifice for Planetary Pacification and Prosperity
उच्छ्रायविस्तराभ्यां च तृतीया चतुरङ्गुला द्व्यङ्गुलश्चेति विस्तारः पूर्वयोरेव शस्यते //
ucchrāyavistarābhyāṃ ca tṛtīyā caturaṅgulā dvyaṅgulaśceti vistāraḥ pūrvayoreva śasyate //
In terms of height and breadth, the third measure is four aṅgulas, and the breadth is said to be two aṅgulas; thus, this rule of breadth is recommended specifically for the two earlier types as well.
This verse is not about Pralaya; it belongs to the Matsya Purana’s Vastuvidya/iconography material, prescribing proportional measurements (aṅgula-based) for form, height, and breadth.
It relates indirectly: kings and householders who sponsor temples and images are advised to follow correct śāstric proportions, since proper measurement is treated as a dharmic requirement for valid construction and worship.
It gives a precise proportional rule: a “third” standard is four aṅgulas (in the relevant dimension) and a two-aṅgula breadth, with the breadth-rule recommended for the two previously described types as well—useful for sculpture/temple component sizing.