Shatapatha Brahmana 2.6.1.29

2.6.1.29

athāha pitṛbhyo 'gniṣvāttebhyo 'nubrūhīti | sa upastṛṇīta ājyamathāsya manthasyāvadyati sa tenaiva saha puroḍāśasya tena saha dhānānāṃ tatsakṛdavadadhātyathopariṣṭāddvirājyasyābhighārayati pratyanaktyavadānāni nātikrāmatīta evopotthāyāśrāvyāha pitṝnagniṣvāttānyajeti vaṣaṭkṛte juhoti

Thereupon he says, 'Pronounce the invitatory prayer to the fathers, consumed by the fire!' He then makes an under-layer of butter, takes a cutting from (the south part of) the porridge, and therewith some of the cake and the parched grains; puts down all this at the same time (in the guhû); makes two sprinklings of butter thereon, and re-anoints (the places of) the cuttings. He does not walk across; but having stepped up (to the fire) on the same side, and called for the 'Sraushat,' he says, 'Pronounce the offering-prayer to the fathers, consumed by the fire!' and pours out the oblation as soon as the Vashat has been uttered.