The Compendium of Suśruta 6.28.9

Suśrutasaṃhitā 6.28.9

snānaṃ trirātraṃ niśi catvareṣu kuryāt puraṃ śāliyavairnavaistu/
adbhiśca gāyatryabhimantritābhiḥ prajvālanaṃ vyāhṛtibhiśca vahneḥ//