Matsya Purana — Vishnu’s Battle with the Daityas: Astra-Combat
अश्वारूढश्च मथनो जम्भकश्चोष्ट्रवाहनः शुम्भो ऽपि विपुलं मेषं समारुह्याव्रजद्रणम् //
aśvārūḍhaśca mathano jambhakaścoṣṭravāhanaḥ śumbho 'pi vipulaṃ meṣaṃ samāruhyāvrajadraṇam //
Mathana, mounted on a horse, and Jambhaka, riding a camel, set out; and Śumbha too, having mounted a huge ram, marched forth to the battlefield.
Nothing directly—this verse is a battlefield scene describing asura leaders and their mounts, not cosmic creation or pralaya.
Indirectly, it functions as narrative context: Purāṇic battle descriptions typically frame the need for righteous protection (kṣātra-dharma), but this specific line only lists who rode which mount and that they advanced to battle.
No Vāstu or ritual procedure is stated; the main technical detail is iconographic—associating named figures with specific vāhanas (mounts), useful for identifying them in Purāṇic storytelling and visual traditions.