Śatapatha Brāhmaṇa ("of a hundred paths") 5.1.3.6

5.1.3.6

tadu tathā na kuryāt | hvalati vā eṣa yo yajñapathādetyeti vā eṣa yajñapathādya evaṃ karoti tasmādyatraivaitareṣām paśūnāṃ vapābhiḥ pracaranti tadevaitasyai vapayā pracareyurekadhāvadānāni śrapayanti na mānuṣyai viśa upaharanti

But let him not do it in this wise; for verily he who departs from the path of the sacrifice, stumbles; and he who does it in this wise certainly departs from the path of the sacrifice. Hence when they proceed with the omenta of the other victims, only then let them proceed with the omentum of that (cow). They cook the portions in one lot, and do not present any to the human kind.