Matsya Purana — Description of the Akṣaya Tṛtīyā Observance
अक्षया संततिस्तस्यास् तस्यां सुकृतमक्षयम् अक्षतैः पूज्यते विष्णुस् तेन साप्यक्षया स्मृता अक्षतैस्तु नराः स्नाता विष्णोर्दत्त्वा तथाक्षतान् //
akṣayā saṃtatistasyās tasyāṃ sukṛtamakṣayam akṣataiḥ pūjyate viṣṇus tena sāpyakṣayā smṛtā akṣataistu narāḥ snātā viṣṇordattvā tathākṣatān //
On that tithi one gains an unbroken line of descendants, and on it merit becomes imperishable. Viṣṇu is worshipped with akṣata (unbroken rice grains); therefore it is remembered as “Akṣayā” (the Imperishable). After bathing, people should also offer those akṣata grains to Viṣṇu.
It does not discuss Pralaya; it focuses on ritual time (a sacred tithi) and the doctrine of ‘akṣaya’ merit—good deeds performed then are said to yield inexhaustible results.
It frames a householder-friendly dharma practice: bathe, worship Viṣṇu, and offer akṣata to gain lasting merit and family continuity (saṃtati). A king, as protector of dharma, would also promote such observances for social and religious stability.
Ritually, it prescribes Viṣṇu-pūjā using akṣata (unbroken rice), emphasizing purity and auspiciousness; there is no Vāstu/temple-measurement rule here, but it directly informs standard pūjā materials and procedure.