Matsya Purana — The Pushkara Manifestation
महीधरान्सर्वनागान् देवी कद्रूर्व्यजायत एवं वृद्धिं समगमन् विश्वे लोकाः परंतप //
mahīdharānsarvanāgān devī kadrūrvyajāyata evaṃ vṛddhiṃ samagaman viśve lokāḥ paraṃtapa //
The goddess Kadrū gave birth to all the Nāgas—those mighty, earth-bearing serpents; and thus, O scorcher of foes, all the worlds attained growth and increase.
It is a creation-and-lineage statement (sarga-style), presenting the Nāgas as “earth-bearers,” implying cosmic stability and increase of the worlds rather than dissolution.
By portraying the worlds’ “growth” as dependent on ordered progeny and stabilizing forces, it supports the Purāṇic ethic that rulers and householders should uphold order (dharma) so society can flourish.
No direct Vāstu or ritual rule is stated; indirectly, Nāgas as stabilizers connect to later Purāṇic traditions where serpent symbolism is used for protection and foundation-guardianship.