Matsya Purana — Bhīma-Dvādaśī
उपाध्यायस्य च पुनर् द्विगुणं सर्वमेव तु ततः प्रभाते विमले समुत्थाय त्रयोदश //
upādhyāyasya ca punar dviguṇaṃ sarvameva tu tataḥ prabhāte vimale samutthāya trayodaśa //
And again, for the preceptor (upādhyāya), all of that should be given in double. Then, rising at the pure dawn, one should thereafter perform the thirteen (rites/offerings).
This verse does not discuss Pralaya; it focuses on dharmic practice—especially proper giving (dāna/fees) and prescribed morning observances.
It teaches respectful patronage of learning: the upādhyāya is to receive double remuneration, and the practitioner should rise at dawn to complete prescribed observances—model duties for both rulers (as patrons) and householders (as practitioners).
Ritual significance: it prescribes a heightened honorarium for the teacher and indicates a structured set of “thirteen” morning acts/offerings to be performed at the pure dawn (prabhāta).