Matsya Purana — Planetary Chariots
परिभ्रमन्ति तद्बद्धाश् चन्द्रसूर्यग्रहा दिवि यावत्तमनुपर्येति ध्रुवं च ज्योतिषां गणः //
paribhramanti tadbaddhāś candrasūryagrahā divi yāvattamanuparyeti dhruvaṃ ca jyotiṣāṃ gaṇaḥ //
Bound to that (cosmic support), the Moon, the Sun, and the planets revolve in the sky, for as long as the host of luminaries continues to circle Dhruva (the Pole Star).
It emphasizes cosmic order and stability: the luminaries keep their courses as long as Dhruva-centered order persists, implying that disruption of this order would belong to dissolution narratives.
By presenting the heavens as rule-bound and orderly, it indirectly supports the Purāṇic ethic that kings and householders should uphold dharma—regularity, restraint, and governance aligned with cosmic law.
While not a Vāstu rule directly, Dhruva functions as a symbol of fixity and orientation; in ritual and sacred planning, fixed directions and stable axes (north/polar orientation) are treated as foundational principles.