Matsya Purana — Śrāddha Procedure: Types
स्वाध्यायकलहं चैव दिवास्वप्नं च सर्वदा अनेन विधिना श्राद्धं निरुद्वास्येह निर्वपेत् //
svādhyāyakalahaṃ caiva divāsvapnaṃ ca sarvadā anena vidhinā śrāddhaṃ nirudvāsyeha nirvapet //
One should always avoid quarrelling during Vedic study (svādhyāya) and sleeping in the daytime; following this procedure, one should here perform the śrāddha offering without driving anyone away (and without causing disturbance).
This verse does not address pralaya; it focuses on ritual discipline and proper conduct during śrāddha.
It teaches the householder (and by extension a ruler overseeing dharma) to maintain restraint and ritual decorum—avoiding disputes during sacred study and avoiding lethargy—so ancestral rites are performed calmly and correctly.
Its significance is ritual: śrāddha should be performed according to prescribed method with controlled behavior, avoiding disruptions (such as quarrels) and not expelling participants/guests, ensuring the rite remains auspicious.