Śatapatha Brāhmaṇa ("of a hundred paths") 1.4.1.40

1.4.1.40

taṃ vā etam | adhvaravantaṃ tricamanvāha devānha vai yajñena yajamānāṃtsapatnā asurā dudhūrṣāṃ cakruste dudhūrṣanta eva na śekurdhūrvituṃ te parābabhūvustasmādyajño 'dhvaro nāma dudhūrṣanha vā enaṃ sapatnaḥ parābhavati yasyaivaṃ viduṣo 'dhvaravantaṃ tricamanvāhuryāvadveva saumyenādhvareṇeṣṭvā jayati tāvajjayati

This tristich, containing (the word) 'cult (adhvara),' he thus recites. For once when the gods were engaged in sacrificing, their rivals, the Asuras, wished to injure (dhurv, dhvar) them; but, though desirous of injuring them, they were unable to injure them and were foiled: for this reason the sacrifice is called adhvara ('not damaged, uninterrupted'); and for whomsoever, that knows this, they recite this tristich containing (the word) adhvara ('cult, sacrifice'), his rival, though desirous of injuring him, is foiled; and he, (the sacrificer), moreover, gains as much as one gains by offering a Soma-sacrifice.