Shatapatha Brahmana 1.1.4.17

1.1.4.17

sā yajna=ameva yajñapātrāṇi praviveśa | tato haināṃ na śekaturnirhantuṃ saiṣāsuraghnī vāgudvadati sa yasya haivaṃviduṣa etāmatra vācam pratyudvādayanti pāpīyāṃso haivāsya sapatnā bhavanti

It entered into the sacrifice itself, into the sacrificial vessels; and thence those two (Asura priests) were unable to expel it. This same Asura-killing, foe-killing voice sounds forth (from the millstones when they are beaten with the wedge). And for whomsoever that knows this, they produce this discordant noise on the present occasion, his enemies are rendered very miserable.