Matsya Purana — Bhīma-Dvādaśī
करिष्यामि यतात्माहं निर्विघ्नेनास्तु तच्च मे एवमुक्त्वा स्वपेद्भूमाव् इतिहासकथां पुनः //
kariṣyāmi yatātmāhaṃ nirvighnenāstu tacca me evamuktvā svapedbhūmāv itihāsakathāṃ punaḥ //
“I shall do it with self-control; may that undertaking of mine be free from obstacles.” Having spoken thus, he lay down and slept upon the ground, and then the text resumes the narrative of the ancient account once again.
This verse does not directly describe pralaya; it functions as a narrative transition emphasizing a vow/resolve and the resumption of an itihāsa (ancient account).
It highlights the dharmic ideal of yatātmatā (self-restraint) and beginning an undertaking with a prayer for nirvighnatā (freedom from obstacles), along with simplicity (sleeping on the ground) associated with discipline and restraint.
No explicit Vāstu or temple-ritual rule appears here; the closest ritual nuance is the customary invocation for an obstacle-free completion of a vowed action (nirvighna-saṅkalpa).