Srimad-Bhagavatam: Canto 6 - Chapter 1 - Verse 18

Sanskrit:

अज्ञानादथवा ज्ञानादुत्तमश्लोकनाम यत् ।सङ्कीर्तितमघं पुंसो दहेदेधो यथानल: ॥ १८ ॥

ITRANS:

ajñānād athavā jñānāduttamaśloka-nāma yatsaṅkīrtitam aghaṁ puṁsodahed edho yathānalaḥ

Translation:

As a fire burns dry grass to ashes, so the holy name of the Lord, whether chanted knowingly or unknowingly, burns to ashes, without fail, all the reactions of one’s sinful activities.

Purport:

Fire will act, regardless of whether handled by an innocent child or by someone well aware of its power. For example, if a field of straw or dry grass is set afire, either by an elderly man who knows the power of fire or by a child who does not, the grass will be burned to ashes. Similarly, one may or may not know the power of chanting the Hare Kṛṣṇa mantra, but if one chants the holy name he will become free from all sinful reactions.