Matsya Purana — Narasimha’s Victory over Hiraṇyakaśipu and the Catalogue of Apocalyptic Omens
संदष्टौष्ठपुटः क्रोधाद् वाराह इव पूर्वजः नदी भागीरथी चैव सरयूः कौशिकी तथा //
saṃdaṣṭauṣṭhapuṭaḥ krodhād vārāha iva pūrvajaḥ nadī bhāgīrathī caiva sarayūḥ kauśikī tathā //
Clenching his lips in anger, like a boar, the elder spoke—(then he mentioned) the rivers Bhāgīrathī (Gaṅgā), Sarayū, and likewise Kauśikī.
This verse does not discuss pralaya; it belongs to a sacred-river context, naming holy rivers and describing an emotional moment in the narrative.
By highlighting renowned tīrthas like Bhāgīrathī, Sarayū, and Kauśikī, it supports the Purāṇic householder/kingly duty of seeking purification and accruing merit through dharmic pilgrimage and ritual bathing.
The ritual takeaway is tīrtha-snāna (bathing/ablutions) and reverence for specific sacred rivers; no Vāstu or temple-construction rule is stated in this verse.