Śatapatha Brāhmaṇa ("of a hundred paths") 2.6.1.5

2.6.1.5

atha pitṛbhyo barhiṣadbhyaḥ | anvāhāryapacane dhānāḥ kurvanti tato 'rdhāḥ piṃṣantyardhā ityeva dhānā apiṣṭā bhavanti tā dhānāḥ pitṛbhyo barhiṣadbhyaḥ

Thereupon they parch barley-grain on the Anvâhâryapakana (or Dakshinâgni) for the Pitaro Barhishadah. They then grind one half of it; and (the other) half remains thus unground,--this is the parched grain for the Barhis-seated fathers.