Tapasya and sound vibration purify the heart, revealing one's eternal identity beyond the body.Listen — Srila Prabhupada Uvaca
Puṣṭa Kṛṣṇa: So we're continuing with this questionnaire from Bhavan's Journal in Bombay. This is question number ten. Question number ten, Śrīla Prabhupāda, is, "Will mantras lose their sanctity if they are not in Sanskrit?" Prabhupāda: Hmm? Puṣṭa Kṛṣṇa: Will mantras lose their sanctity, or holiness, if they are not in the Sanskrit language? Prabhupāda: Mantra in Sanskrit language, it may... The letters may be different, but it is a transcendental sound.
The sound must be vibrated. You cannot translate it. The sound as it is... Just like Hare Kṛṣṇa mahā-mantra, the sound must be produced.
You cannot translate. Then it will be artha, arthavad. That is prohibited. You cannot interpret or do other way.
The sound vibration must be there. Then it will continue in sanctity. Puṣṭa Kṛṣṇa: Is that to say that the mantras can be written in Devanāgarī script or in roman letters, but... Prabhupāda: It doesn't matter. Puṣṭa Kṛṣṇa: But the sound must be the same. Prabhupāda: Yes. The sound is important. Puṣṭa Kṛṣṇa: So the sanctity is in the sound vibration and not so much that it's in the Sanskrit letters itself.
May I ask another question, Śrīla Prabhupāda? "Are fasting and other dietary regulations necessary for leading a spiritual life?" Prabhupāda: Certainly. tapasā brahmacaryeṇa śamena damena va tyāgena sattva-śaucābhyāṁ yamena niyamena vā [SB 6.1.13] To advance in spiritual life these things are essential, tapasyā. Tapasyā means voluntarily accepting something which may be painful. Just like we are recommending no illicit sex, no gambling, no meat-eating.
So those who are accustomed to these bad habits, for them, in the beginning it may be a little difficult. But in spite of becoming difficult, one has to do it. That is called tapasyā. To rise early in the morning, those who are not practiced, it is a little painful, but one has to do it.
So this is called tapasyā. So according to the Vedic injunction, there are some tapasyas that must be done. It is not, "I may do it or not do it." It must be done. Just like in the Muṇḍaka Upaniṣad it is ordered that one must go to the spiritual master.