Matsya Purana — The Array of the Gods: Description of the Vaiṣṇava Host and the Lokapālas
भुजगेन्द्रेण वदने निविष्टेन विराजितम् अमृतारम्भनिर्मुक्तं मन्दराद्रिम् इवोच्छ्रितम् //
bhujagendreṇa vadane niviṣṭena virājitam amṛtārambhanirmuktaṃ mandarādrim ivocchritam //
Adorned by the great serpent set upon (or within) the mouth, it shines forth—lofty like Mount Mandara when freed at the very outset of the churning of nectar.
It does not describe Pralaya directly; instead it uses the churning-of-the-ocean (amṛta) imagery as a poetic comparison to convey brilliance and exalted stature.
Indirectly, it supports dharma through correct worship: a king or householder is to commission, honor, and install images according to śāstra, where even ornament-details (like a serpent-lord motif) carry prescribed symbolic meaning.
The verse functions as pratima-lakṣaṇa: it specifies a visual feature (the serpent-lord placed at the face/mouth area) that guides sculptors and priests in creating and recognizing a properly formed icon for temple installation.