Matsya Purana — Śrāddha Procedure: Types
आचान्तेषु पुनर्दद्याज् जलपुष्पाक्षतोदकम् स्वस्तिवाचनकं सर्वं पिण्डोपरि समाहरेत् //
ācānteṣu punardadyāj jalapuṣpākṣatodakam svastivācanakaṃ sarvaṃ piṇḍopari samāharet //
After they have performed ācamana (ritual sipping of water), one should again offer water together with flowers and unbroken grains (akṣata); and one should gather and place all the auspicious recitations (svasti-formulas) over the piṇḍa (rice-ball offering).
This verse does not address pralaya; it focuses on correct śrāddha procedure—post-ācamana offerings and auspicious recitations placed over the piṇḍa.
It outlines a householder’s dharma in performing ancestor rites: after ācamana, offer udaka with flowers and akṣata and conclude with svasti-recitation arranged over the piṇḍa, emphasizing orderly, auspicious completion of śrāddha.
The significance is ritual (not architectural): it prescribes the sequence—ācamana, then a renewed water-offering with flowers and akṣata, and the formal placement/association of svasti-vācanas with the piṇḍa offering.