Matsya Purana — Ekoddiṣṭa Śrāddha
जनने ऽप्येवमेव स्यात् सर्ववर्णेषु सर्वदा तथास्थिसंचयाद् ऊर्ध्वम् अङ्गस्पर्शो विधीयते //
janane 'pyevameva syāt sarvavarṇeṣu sarvadā tathāsthisaṃcayād ūrdhvam aṅgasparśo vidhīyate //
The same rule applies at birth as well, for all varṇas at all times; and likewise, after the gathering of the bones (following cremation), bodily contact is again permitted.
This verse does not address Pralaya; it focuses on ritual purity rules (aśauca) connected with birth and post-cremation observances.
It gives a practical dharma rule for managing purity restrictions: after the prescribed stage—specifically, after asthi-saṃcaya—normal social interaction like bodily contact becomes permissible again, helping householders (and rulers overseeing social order) regulate conduct consistently across all varṇas.
The ritual point is asthi-saṃcaya (collection of bones after cremation) as a key threshold after which aṅga-sparśa (physical contact) is allowed—an actionable detail in Matsya Purana samskāra/antyeṣṭi procedure rather than Vāstu or temple architecture.