Śatapatha Brāhmaṇa ("of a hundred paths") 3.1.4.3

3.1.4.3

yajñena vai devāḥ | imāṃ jitiṃ jigyuryaiṣāmiyaṃ jitiste hocuḥ kathaṃ na idam manuṣyairanabhyārohyaṃ syāditi te yajñasya rasaṃ dhītvā yathā madhu madhukṛto nirdhayeyurviduhya yajñaṃ yūpena yopayitvā tiro 'bhavannatha yadenenāyopayaṃstasmādyūpo nāma

By means of the sacrifice the gods obtained that supreme authority which they now wield. They spake, 'How may this (world) of ours be unattainable by men!' They then sipped the sap of the sacrifice, as bees would suck out honey; and having drained the sacrifice and effaced its traces by means of the sacrificial stake, they disappeared: and because they effaced (scattered, yopaya) therewith, therefore it is called yûpa (stake).