Matsya Purana — Pṛthu
प्रेतरक्षोगणैर्दुग्धा धरा रुधिरमुल्बणम् रौप्यनाभो ऽभवद्दोग्धा सुमाली वत्स एव तु //
pretarakṣogaṇairdugdhā dharā rudhiramulbaṇam raupyanābho 'bhavaddogdhā sumālī vatsa eva tu //
Then the Earth was ‘milked’ by hosts of Pretas and Rākṣasas, and what flowed forth was thick, abundant blood. Raupyanābha became the milker, and Sumālī indeed was the calf.
Rather than describing Pralaya directly, this verse presents a creation-era cosmological motif: different beings “milk” the Earth to draw out substances aligned with their nature—here, pretas and rākṣasas obtain blood, a symbol of their tamasic, violent association.
By contrastive symbolism: a ruler or householder should “draw” resources from the Earth through dharmic means (nurturing, protection, right governance). When exploitative or impure agents dominate, the yield becomes destructive (blood), implying that extraction without dharma harms society and the land.
No direct Vāstu or temple-building rule is stated; the ritual-cosmological idea is that substances used in rites (milk, ghee, soma, etc.) have mythic origins. This verse specifically explains a blood-yield variant in the Earth-milking cycle, useful for interpreting Purāṇic ritual symbolism rather than construction procedure.