Matsya Purana — The Pushkara Manifestation
पुत्रं च शंभवे चैकं समुत्पादितवानृषिः तस्याग्रे वाग्यतस्तस्थौ ब्रह्मा तामसमव्ययम् //
putraṃ ca śaṃbhave caikaṃ samutpāditavānṛṣiḥ tasyāgre vāgyatastasthau brahmā tāmasamavyayam //
The sage brought forth a single son for Śambhu (Śiva). Before him, Brahmā stood silent—restraining speech—abiding in his imperishable tāmasa (dark, inert) mode.
It points to a creation-phase motif where Brahmā operates through a tāmasa mode—symbolizing inert/dark potency—suggesting that even generative acts can arise from guṇa-conditioned states within cyclic cosmology.
Through the image of Brahmā as vāg-yata (speech-restrained), it implicitly praises self-control (niyama). For kings and householders, disciplined speech and restraint are ethical foundations for governance, ritual correctness, and social harmony.
No direct Vāstu or temple rule is stated, but the ritual principle of vāg-niyama (silence/restraint) is relevant to consecrations and vows, where controlled speech is treated as a source of purity and efficacy.