Matsya Purana — Characteristics of Dvāpara and Kali Yugas
द्वैधमुत्पद्यते चैव युगे तस्मिञ्श्रुतिस्मृतौ द्विधा श्रुतिः स्मृतिश्चैव निश्चयो नाधिगम्यते //
dvaidhamutpadyate caiva yuge tasmiñśrutismṛtau dvidhā śrutiḥ smṛtiścaiva niścayo nādhigamyate //
In that age, a duality arises concerning Śruti and Smṛti: both Śruti and Smṛti become divided, and a clear determination (of what is right) cannot be ascertained.
This verse does not describe Pralaya directly; it highlights a yuga-condition where scriptural guidance becomes internally divided, making dharma harder to determine—an ethical symptom of decline rather than a cosmological dissolution.
It warns that in certain yugas even authoritative sources (Śruti/Smṛti) appear conflicting; a king or householder must therefore be cautious in judging dharma, seeking well-grounded interpretation and consistent principles rather than relying on a single contested citation.
No direct Vāstu or temple-rule is stated; indirectly, it implies that ritual/temple prescriptions may also appear divergent in some ages, so one should follow coherent, well-attested traditions and careful adjudication when texts disagree.