Śatapatha Brāhmaṇa ("of a hundred paths") 3.7.1.29

3.7.1.29

taṃ ha smaitaṃ devā anupraharanti | yathedamapyetarhyeke 'nupraharantīti devā akurvanniti tato rakṣāṃsi yajñamanūdapibanta

Now the gods once threw it after (the prastara into the fire) even as now some throw it after, thinking, 'So the gods did it.' Thereupon the Rakshas sipped the sacrifice (Soma) after (the gods).