Matsya Purana — The Greatness and Procedure of the Sarva-Phala-Tyaga Vrata
यथा फलान्यनन्तानि शिवभक्तेषु सर्वदा तथानन्तफलावाप्तिर् अस्तु जन्मनि जन्मनि //
yathā phalānyanantāni śivabhakteṣu sarvadā tathānantaphalāvāptir astu janmani janmani //
As the fruits of merit are ever infinite for the devotees of Śiva, so may the attainment of infinite fruits be ours—birth after birth.
This verse does not address pralaya directly; it is a phala-śruti style statement emphasizing that Śiva-devotion yields inexhaustible merit across repeated births.
It frames bhakti as a universally accessible dharma: a householder or king who supports and practices Śiva-worship (with faith, vows, gifts, and ethical conduct) is said to gain enduring merit that continues across lifetimes.
No specific vāstu/temple rule is stated; ritually, it functions as a concluding benediction affirming that Śiva-upāsanā (worship/devotion) produces limitless spiritual ‘fruit’ over many births.