Matsya Purana — Description of Gomedaka and Puṣkara Dvīpas; the Lokāloka Boundary; Ocean Tide...
तस्मात्परिमिता भेदाः स्मृताः कार्यात्मकास्तु वै ते कारणात्मकाश्चैव स्युर्भेदा महदादयः //
tasmātparimitā bhedāḥ smṛtāḥ kāryātmakāstu vai te kāraṇātmakāścaiva syurbhedā mahadādayaḥ //
Therefore, the distinct categories are said to be limited in number. Some are of the nature of effects; and those categories beginning with Mahat are also of the nature of causes.
It frames creation in terms of limited, countable principles (tattvas) where some are effects and some—like Mahat—function as causes, implying a structured causal chain that can also reverse during dissolution.
By distinguishing causes from effects, it supports a dharmic ethic of discernment: rulers and householders should identify root causes (kāraṇa) behind social disorder or personal suffering rather than merely reacting to outcomes (kārya).
No direct Vāstu or ritual rule is stated; the takeaway is conceptual—ritual and temple works are ‘effects’ (kārya) grounded in prior ‘causes’ (kāraṇa) such as intention, prescription (vidhi), and foundational principles.