CHĀNDOGYA UPANISHAD · 5.24.3

तद् यथेषीकातूलम् अग्नौ प्रोतं प्रदूयेतैवं हास्य सर्वे पाप्मानः प्रदूयन्ते य एतद् एवं विद्वान् अग्निहोत्रं जुहोति ॥

tad yatheṣīkātūlam agnau protaṃ pradūyetaivaṃ hāsya sarve pāpmānaḥ pradūyante ya etad evaṃ vidvān agnihotraṃ juhoti ॥

'As the soft fibres of the Ishîkâ reed, when thrown into the fire, are burnt, thus all his sins are burnt whoever offers this Agnihotra with a full knowledge of its true purport.