Matsya Purana — Bhīma-Dvādaśī
कृत्वा वै ब्राह्मणान् सर्वान् अन्नैर्नानाविधैस्तथा भुक्त्वा चाक्षारलवणम् आत्मना च विसर्जयेत् //
kṛtvā vai brāhmaṇān sarvān annairnānāvidhaistathā bhuktvā cākṣāralavaṇam ātmanā ca visarjayet //
After duly feeding all the brāhmaṇas with various kinds of foods, and having himself eaten alkaline salt as well, he should then dismiss them respectfully.
This verse does not address pralaya; it focuses on dharmic ritual conduct—feeding brāhmaṇas, a small act of self-observance, and formally concluding the rite by respectfully dismissing them.
It reflects the householder/royal duty of hospitality and dāna: provide varied, proper food to brāhmaṇas, observe a prescribed personal dietary/purificatory act, and complete the ceremony with formal visarga (dismissal), emphasizing orderly, respectful ritual completion.
The significance is ritual (not architectural): it outlines a sequence—brāhmaṇa-bhojana (feeding), the performer’s own consumption of kṣāra-lavaṇa (alkaline salt as a purificatory/rite-linked item), and visarjana (formal dismissal), indicating proper closure of a religious observance.