Matsya Purana — Division of Bhārata-varṣa
उत्सेधो वृक्षराजस्य दिवम् आवृत्य तिष्ठति तस्य जम्बूफलरसो नदी भूत्वा प्रसर्पति //
utsedho vṛkṣarājasya divam āvṛtya tiṣṭhati tasya jambūphalaraso nadī bhūtvā prasarpati //
The towering height of the king of trees rises and stands, as though covering the sky; and the juice of its jambū fruits pours forth, becoming a river and spreading out.
This verse is cosmographic rather than pralaya-centered: it describes the wondrous, world-structuring features of Jambūdvīpa—especially the immense Jambu tree and a river formed from its fruit-juice—showing how Puranic geography explains the origins of sacred rivers and substances.
Indirectly, it supports dharma by grounding human life in a sacred cosmic order: kings and householders are encouraged to honor tīrthas (sacred waters) and uphold rituals and charity connected with rivers, since such waters are portrayed as divinely originated and cosmically significant.
No direct Vāstu rule appears in this verse, but it reinforces ritual geography: rivers are sacred resources for purification (snāna), offerings (arghya), and consecrations (abhiṣeka), which are central to temple ritual practice in the broader Matsya Purana tradition.