Śatapatha Brāhmaṇa ("of a hundred paths") 9.3.4.15

9.3.4.15

āspṛṣṭam pariśritaḥ | tadyatkṛṣṇājinamāspṛṣṭam pariśrito bhavati tatho hāsyaiṣa daiva ātmā kṛṣṇājine 'bhiṣikto bhavatyatha yadenamanvārabdhamagniṃ tiṣṭhantamabhiṣiñcati tathā haitasmāddaivādabhiṣekānna vyavacidyate

Close to the enclosing-stones: inasmuch as the black-antelope skin is close to the enclosing-stones, so that divine body of his is consecrated on the black-antelope skin; and inasmuch as he is consecrated whilst keeping hold of the fire-altar he is not cut off from that divine consecration (of the Fire).