Matsya Purana — The Ārdrānandakarī Tṛtīyā Vrata: Ritual Procedure
आर्द्रानन्दकरी नाम्ना तृतीयैषा सनातनी यामुपोष्य नरो याति शम्भोर्यत्परमं पदम् //
ārdrānandakarī nāmnā tṛtīyaiṣā sanātanī yāmupoṣya naro yāti śambhoryatparamaṃ padam //
The third observance is the eternal vow known as Ārdrānandakarī. By fasting in accordance with it, a man attains the supreme abode that belongs to Śambhu (Śiva).
This verse does not discuss pralaya; it focuses on vrata-phala—how a specific fast (Ārdrānandakarī) leads to attaining Śiva’s supreme abode.
It presents upavāsa (religious fasting) as a dharmic discipline available to householders (and rulers) alike—an ethical-spiritual practice that purifies conduct and directs life toward the highest goal (parama pada).
The ritual significance is the observance of a named vrata through fasting; no Vāstu/temple-building rule appears in this specific verse.