Matsya Purana — Cosmography of Jambūdvīpa: Varṣas
नाभीबन्धनसम्भूतो ब्रह्मणो ऽव्यक्तजन्मनः पूर्वतः श्वेतवर्णस्तु ब्राह्मण्यं तस्य तेन वै //
nābhībandhanasambhūto brahmaṇo 'vyaktajanmanaḥ pūrvataḥ śvetavarṇastu brāhmaṇyaṃ tasya tena vai //
Born from the navel-bond of Brahmā, whose origin is unmanifest, there arose first one of white complexion; and by that very mark his Brahmin status is affirmed.
It supports a creation (sarga) framework: Brahmā is described as arising from the Unmanifest (avyakta), and from that cosmic origin the first social classification (Brahminhood) is presented as emerging in sequence.
By grounding “brāhmaṇya” in primordial order, the verse underwrites the dharmic model where kings protect the social-religious functions of Brahmins (teaching, ritual guidance), and householders support them through prescribed duties like charity and hospitality.
No direct Vāstu or temple-rule detail appears here; its ritual relevance is indirect—affirming Brahminhood as foundational to yajña/ritual transmission, which later chapters connect to correct rites and consecrations.