Śatapatha Brāhmaṇa ("of a hundred paths") 2.3.2.6

2.3.2.6

yajamānadevatyo vai gārhapatyaḥ | athaiṣa bhrātṛvyadevatyo yadanvāhāryapacanastasmādetaṃ nāharaharāhareyurna ha vā asya sapatnā bhavanti yasyaivaṃ viduṣa etaṃ nāharaharāharantyanvāhāryapacano vā eṣaḥ

Now the Gârhapatya (householder's fire) has the sacrificer for its deity; and the Anvâhâryapakana (southern fire) has his foe for its deity: hence they should not take over that (southern fire) every day (from the Gârhapatya); and he indeed has no enemies, for whomsoever, knowing this, they do not take it over every day. Indeed, it is the Anvâhâryapakana.