Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 9 · Vastu, Griha Pravesha
वास्तु गृहप्रवेशश्च
वृत्येटिका स्वर्णरेणुधान्यशैवलसंयुतम् ।गृहमध्ये हस्तमात्रे गर्ते न्यासाय विन्यसेत् ॥ ५७१ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 571.
Dig a pit one hand deep in the middle of the house. Place a round brick in it, with gold dust, grain and water moss. This is the foundation deposit.
Simple meaning: Place a brick with gold dust, grain and moss in a pit in the middle of the house.
वस्त्वायामदलं नाभिस्तस्मादध्यंगुलत्रयम् ।
Fix the peg at the belly point of the plot. It makes sons and grandsons grow.
चतुर्विंशत्त्रयोविंशत्षोडशद्वादशांगुलैः ।
The measure is 24, 23, 16 or 12 finger-widths for the four classes. The peg is dressed with gold and cloth.
खदिरार्जुनशालोत्थं युगयंत्रं तरूद्भवम् ।
The peg is made of wood such as khadira, arjuna, shala or red sandalwood.