Śatapatha Brāhmaṇa ("of a hundred paths") 3.6.2.26

3.6.2.26

yā vai prajā yajñe 'nanvābhaktāḥ | parābhūtā vai tā evamevaitadyā imāḥ prajā aparābhūtāstā yajña ābhajati manuṣyānanu paśavo devānanu vayāṃsyoṣadhayo vanaspatayo yadidaṃ kiṃ caivamu tatsarvaṃ yajña ābhaktaṃ te ha smaita ubhaye devamanuṣyāḥ pitaraḥ sampibante saiṣā sampā te ha sma dṛśyamānā eva purā sampibanta utaitarhyadṛśyamānāḥ

But those creatures which are not admitted to the sacrifice are forlorn; wherefore he now admits to the sacrifice those creatures here on earth that are not forlorn; behind the men are the beasts; and behind the gods are the birds, the plants, and the trees; and thus whatsoever exists here on earth all that is admitted to the sacrifice. And verily both the gods and men, and the Fathers drink together, and this is their symposium; of old they drank together visibly, but now they do so unseen.