Matsya Purana — Description of the Akṣaya Tṛtīyā Observance
एकामप्युक्तवत्कृत्वा तृतीयां विधिवन्नरः एतासामपि सर्वासां तृतीयानां फलं भवेत् //
ekāmapyuktavatkṛtvā tṛtīyāṃ vidhivannaraḥ etāsāmapi sarvāsāṃ tṛtīyānāṃ phalaṃ bhavet //
If a person performs even a single Tṛtīyā observance exactly as stated and in due ritual order, he obtains the full merit that is said to arise from all such Tṛtīyā rites.
This verse does not address Pralaya; it focuses on ritual efficacy, stating that correctly performing even one prescribed Tṛtīyā observance yields the merit associated with all such Tṛtīyā rites.
It emphasizes dharmic discipline: a householder (and likewise a king) gains religious merit not by quantity alone but by performing a vow/rite with proper procedure (vidhi), attention, and fidelity to scriptural instruction.
The significance is ritual rather than architectural: the verse is a phala-śruti asserting that one correctly executed Tṛtīyā rite can confer comprehensive merit, highlighting the importance of vidhivan performance.