Matsya Purana — The Greatness and Procedure of the Aṅgāra
*शुक्र उवाच चतुर्थ्यङ्गारकदिने यदा भवति दानव मृदा स्नानं तदा कुर्यात् पद्मरागविभूषितः //
*śukra uvāca caturthyaṅgārakadine yadā bhavati dānava mṛdā snānaṃ tadā kuryāt padmarāgavibhūṣitaḥ //
Śukra said: “O Dānava, when the fourth lunar day (Caturthī) falls on a Tuesday (Aṅgāraka-day), one should then perform a purificatory bath with sacred earth (mṛdā), adorned with a padmarāga ruby.”
This verse does not address Pralaya; it focuses on dharmic timing (tithi–weekday combination) and a ritual bath for auspicious merit.
It gives a householder-style dharma observance: when a specific calendrical combination occurs (Caturthī on Tuesday), one should undertake purification (mṛdā-snāna) and auspicious adornment, reflecting disciplined ritual conduct encouraged in Purāṇic ethics.
The ritual significance is the prescribed mṛdā-snāna (bath using purifying earth) performed on a specific tithi–vāra yoga, along with padmarāga (ruby) adornment as an auspicious accessory.