[2][3] Pavitra Mantra is mentioned as the 12th verse in the 80th chapter of the Patalakhanda in the Hindu puranic text Padma Purana.
[4] "ॐ अपवित्र: पवित्रो वा सर्वावस्थां गतोपि वा। य: स्मरेत् पुण्डरीकाक्षं स: बाह्याभंतर: शुचि:।।"In the Mantra, the name of Lord Vishnu is mentioned as Pundarikaksha.
The mantra starts with the sacred letter Om which signifies the symbol of ultimate truth Brahman in Hinduism.
In the Mantra, it is said that if one is impure or sacred or even in all other situations, then remembering the name Pundarikaksha which is another name of Lord Vishnu, one becomes purified from within as well as from outside self.
Similarly before starting a Puja, the holy water is consecrated by splashing it on oneself and on the worship materials.