Matsya Purana — Brahmā–Gāyatrī as a Divine Pair and the Early Genealogies of Creation
पितृकन्या सुनीथा तु वेनमङ्गादजीजनत् वेनमन्यायिनं विप्रा ममन्थुस् तत्कराद् अभूत् पृथुर्नाम महातेजाः स पुत्रौ द्वाव् अजीजनत् //
pitṛkanyā sunīthā tu venamaṅgādajījanat venamanyāyinaṃ viprā mamanthus tatkarād abhūt pṛthurnāma mahātejāḥ sa putrau dvāv ajījanat //
Sunīthā, the daughter of Pitṛ (Yama), bore Vena by King Aṅga. When that unrighteous Vena was churned by the sages, from his hand there arose the greatly radiant one named Pṛthu; and he in turn begot two sons.
This verse is not about Pralaya; it belongs to the dynasty narrative, showing how an unrighteous king (Vena) is removed and a righteous ruler (Pṛthu) is produced for restoring order.
It frames kingship as a moral office: adharma in a ruler leads to corrective action by the guardians of dharma (sages), while a worthy king like Pṛthu is portrayed as the restorer of righteous governance and social stability.
No Vāstu or temple-building rule is stated in this verse; the only ritual-like motif is the sages “churning” Vena, a symbolic act of extracting a new, dharmic sovereign from a corrupted kingship.