Matsya Purana — Navagraha Sacrifice for Planetary Pacification and Prosperity
वप्रद्वयावृतां वेदिं वितस्त्युच्छ्रायसंमिताम् संस्थापनाय देवानां चतुरस्रामुदङ्मुखाम् //
vapradvayāvṛtāṃ vediṃ vitastyucchrāyasaṃmitām saṃsthāpanāya devānāṃ caturasrāmudaṅmukhām //
For establishing the deities, one should set up a square altar (vedī), enclosed by two embankments, measured to a height of one vitasti, and oriented facing north.
This verse is not about Pralaya; it focuses on ritual-architectural procedure—how to construct and orient an altar for installing deities.
It supports the duty of maintaining dharmic worship: kings and householders are instructed to follow correct measurements and directions when establishing deities, ensuring rites are performed according to śāstra.
It specifies a technical Vastu/ritual standard: a square altar, bounded by two embankments, with a prescribed height (one vitasti) and a north-facing orientation for deva installation.