Śatapatha Brāhmaṇa ("of a hundred paths") 5.2.4.13

5.2.4.13

sa ya eṣa āgneyo 'ṣṭākapālaḥ puroḍāśo bhavati | so 'gnereko bhāgo 'tha yadvāruṇo yavamayaścarurbhavati yo vai varuṇaḥ so 'gniḥ so 'gnerdvitīyo bhāgo 'tha yadraudro gāvedhukaścarurbhavati yo vai rudraḥ so 'gniḥ so 'gnestṛtīyo bhāgo 'tha yadgāvedhuko bhavati vāstavyo vā eṣa devo vāstavyā gavedhukāstasmādgāvedhuko bhavatyatha yadanaḍuhyai vahalāyā aindraṃ dadhi bhavati sa indrasya caturtho bhāgo yadvai caturthaṃ tatturīyaṃ tasmādindraturīyaṃ nāma tasyaiṣaivānaḍuhī vahalā dakṣiṇā sā hi vahenāgneyyagnidagdhamiva hyasyai vaham bhavatyatha yatstrī satī vahatyadharmeṇa tadasyai vāruṇaṃ rūpamatha yadgaustena raudryatha yadasyā aindraṃ dadhi tenaindryeṣā hi vā etatsarvaṃ vyaśnute tasmādeṣaivānaḍuhī vahalā dakṣiṇā

Now what cake on eight potsherds there is for Agni, that is one of Agni's shares; and what barley pap there is for Varuna--Varuna being the same as Agni--that is Agni's second share; and what pap of gavedhukâ seed there is for Rudra--Rudra being the same as Agni--that is Agni's third share. And as to why it is prepared of gavedhukâ seed: that god surely is (the recipient) of refuse (remains of offering), and gavedhukâ grass is refuse,--hence it is prepared of gavedhukâ seed. And what mess of sour curds there is from a yoke-trained cow for Indra, that is the fourth share (being that) of Indra--turîya being the same as katurtha (fourth)--hence the name Indraturîya. That same yoke-trained cow is the fee for this (offering); for by her shoulder she is of Agni's nature, since her shoulder is, as it were, fire-burnt; and in that, being a female, she improperly draws (the cart), that is her Varunic nature; and in that she is a cow, she is of Rudra's nature; and in that Indra's sour curds (come) from her, thereby she is of Indra's nature. Indeed that (cow) commands all that: therefore that same yoke-trained cow is the fee.