Srimad-Bhagavatam: Canto 4 - Chapter 1 - Verse 28

Sanskrit:

वयं मरुत्वन्तमिहार्थनाशनंह्वयामहे त्वच्छ्रवसा हतत्विषम् । अयातयामोपहवैरनन्तरंप्रसह्य राजन् जुहवाम तेऽहितम् ॥ २८ ॥

ITRANS:

vayaṁ marutvantam ihārtha-nāśanaṁhvayāmahe tvac-chravasā hata-tviṣamayātayāmopahavair anantaraṁprasahya rājan juhavāma te ’hitam

Translation:

Dear King, Indra’s powers are already reduced due to his attempt to impede the execution of your sacrifice. We shall call him by Vedic mantras which were never before used, and certainly he will come. Thus by the power of our mantra, we shall cast him into the fire because he is your enemy.

Purport:

By chanting the Vedic mantras properly in a sacrifice, one can perform many wonderful things. In Kali-yuga, however, there are no qualified brāhmaṇas who can chant the mantras properly. Consequently no attempt should be made to perform such big sacrifices. In this age the only sacrifice recommended is the saṅkīrtana movement.