Matsya Purana — Cosmography of Śākadvīpa and Successive Dvīpas: Mountains
गौरी कुमुद्वती चैव संध्या रात्रिर्मनोजवा ख्याती च पुण्डरीका च गङ्गा सप्तविधा स्मृता //
gaurī kumudvatī caiva saṃdhyā rātrirmanojavā khyātī ca puṇḍarīkā ca gaṅgā saptavidhā smṛtā //
Gaṅgā is remembered as sevenfold: Gaurī, Kumudvatī, Saṃdhyā, Rātri, Manojavā, Khyātī, and Puṇḍarīkā.
This verse does not describe pralaya directly; it instead classifies Gaṅgā into seven named forms, a typical tīrtha-mahātmya style enumeration used for worship, remembrance, and sacred geography.
By prescribing recognizable names/forms of Gaṅgā, it supports householders (and rulers who sponsor public rites) in performing Gaṅgā-related practices—such as bathing (snāna), offerings (arghya), and name-recitation (nāma-japa)—which the Purāṇas treat as meritorious duties sustaining dharma.
Ritually, the verse functions as a canonical name-list for invoking Gaṅgā in japa and pūjā; such enumerations are often used when consecrating water (jala-saṃskāra) or during river-bath vows. No specific Vāstu/temple-measurement rule is stated in this line.