Oct 01, 2017 INDIA (SUN)
oṁ apavitraḥ pavitro vā
sarvāvasthāṁ gato 'pi vā
yaḥ smaret puṇḍarīkākṣaṁ
sa bahyābhyantara-śuciḥ
śrī viṣṇu śrī viṣṇu śrī viṣṇu
Srila Prabhupada: This purification, how it is done? Now, yaḥ smaret, "one who remembers," puṇḍarīkākṣaṁ, "Kṛṣṇa, always," sa bāhya, means "externally," and abhyantaram, "internally," śuci, "purified." So if you chant Hare Kṛṣṇa always, either loudly or silently or within yourself, mind, if you chant, so there is no question of impurification. It is... You remain always in, what is called, antiseptic stage, or prophylactic stage. Purification is there simply by remembering Kṛṣṇa."
(Lecture on SB 7.9.11-13 -- Hawaii, March 24,1969)