Śatapatha Brāhmaṇa ("of a hundred paths") 9.3.4.10

9.3.4.10

athainaṃ kṛṣṇājine 'bhiṣiñcati | yajño vai kṛṣṇājinaṃ yajña evainametadabhiṣiñcati lomataścandāṃsi vai lomāni candaḥsvevainametadabhiṣiñcatyuttaratastasyopari bandhuḥ prācīnagrīve taddhi devatrā

He then anoints him on a black antelope skin,--for the black antelope skin is (a symbol of) the sacrifice: it is thus at the sacrifice that he anoints him. On the hairy side (of the skin),--for the hairs are the metres: on the metres he thus anoints him. On the left (north) side (of the fire-altar he anoints him): the significance of this (will be explained) further on. On (the skin laid down) with the neck-part towards the front, for that (tends) godwards.