Matsya Purana — Saptamī Sacred Bath and the Mṛtavatsābhiṣeka Rite for Pacifying Misfortune an...
भुक्त्वा च गुरुणा चेयम् उच्चार्या मन्त्रसंततिः दीर्घायुरस्तु बालो ऽयं यावद्वर्षशतं सुखी //
bhuktvā ca guruṇā ceyam uccāryā mantrasaṃtatiḥ dīrghāyurastu bālo 'yaṃ yāvadvarṣaśataṃ sukhī //
After (the rite/meal) has been completed, the teacher should recite this continuous series of mantras: “May this child be long-lived; may he remain happy for as long as a hundred years.”
This verse does not discuss Pralaya; it focuses on an auspicious ritual benediction (āyuṣya) pronounced for a child’s longevity and happiness.
It reflects the householder’s dharma of performing samskaras and seeking welfare for dependents; it also implies the social duty of honoring the guru’s role in correctly concluding rites with proper mantras and blessings.
Ritually, it specifies the correct sequencing: after the concluding act (bhuktvā), the guru recites a prescribed mantra-series blessing the child with a full lifespan (up to 100 years) and happiness.