Matsya Purana — The Greatness of the Vibhūti-Dvādaśī Vow: Pushkara
इत्युक्त्वा स मुनिर् ब्रह्मंस् तत्रैवान्तरधीयत राजा यथोक्तं च पुनर् अकरोत्पुष्पवाहनः //
ityuktvā sa munir brahmaṃs tatraivāntaradhīyata rājā yathoktaṃ ca punar akarotpuṣpavāhanaḥ //
Having spoken thus, that sage—O Brahman—vanished there itself; and the king, Puṣpavāhana, again carried out exactly as had been instructed.
This verse does not address pralaya directly; it emphasizes narrative closure—after giving instructions, the sage disappears, and the king proceeds to act exactly as told.
It highlights a key Rajadharma principle: a ruler should faithfully implement prescribed counsel (especially from sages/teachers) without alteration, showing discipline and adherence to dharma.
The explicit point is correct ritual/command compliance—“yathoktam” indicates performing a rite or duty exactly according to injunction, a standard principle also applied in Vastu and temple-ritual procedures.