Matsya Purana — Soma
इत्येते पितरो देवा देवाश्च पितरश्च वै अन्योन्यपितरो ह्येते देवाश्च पितरो दिवि //
ityete pitaro devā devāśca pitaraśca vai anyonyapitaro hyete devāśca pitaro divi //
Thus, these Pitṛs (Ancestors) are also the Gods, and the Gods indeed are also the Pitṛs. They are mutually each other’s progenitors; and in heaven the Gods themselves are the Pitṛs.
This verse is not about Pralaya; it teaches ritual-metaphysical identity: Devas and Pitṛs are presented as mutually connected and effectively one continuum in the heavenly order.
By equating Pitṛs with Devas, the verse elevates śrāddha and ancestor-offerings as a core duty of householders (and kings as exemplars), implying that honoring Pitṛs is tantamount to honoring the gods and sustaining dharmic order.
The significance is ritual (not architectural): it supports the authority of śrāddha/ancestor rites by stating that offerings to Pitṛs reach a divine level, since Devas and Pitṛs are treated as interlinked in heaven.