Matsya Purana — Purūravas Witnesses the Sports of Apsarases and Gandharvas; Attains the Grace...
एवमेतन्महीपाल नात्र कार्या विचारणा एवं प्रसादं सम्प्राप्य देवदेवाज्जनार्दनात् //
evametanmahīpāla nātra kāryā vicāraṇā evaṃ prasādaṃ samprāpya devadevājjanārdanāt //
So it is, O king; there is no need for deliberation here. Thus, having obtained such grace from Janārdana, the God of gods, one attains the intended good.
This verse does not describe pralaya or cosmology; it stresses certainty in dharma once divine grace (prasāda) from Janārdana is obtained.
It frames royal decision-making as grounded in dharma and devotion: a king should not waver in doubt when righteous counsel is aligned with the grace of Viṣṇu (Janārdana).
No direct vāstu/temple rule is stated; the ritual takeaway is the primacy of receiving and honoring divine prasāda as confirmation of the proper course.