Śatapatha Brāhmaṇa ("of a hundred paths") 3.8.2.25

3.8.2.25

sa ha sma bāhū anvavekṣyāha | imau palitau bāhū kva svidbrāhmaṇasya vaco babhūveti na tadādriyetottamo vā eṣa prayājo bhavatīdaṃ vai haviryajña uttame prayāje dhruvāmevāgre 'bhighārayati tasyai hi prathamāvājyabhāgau hoṣyanbhavati vapāṃ vā atra prathamāṃ hoṣyanbhavati tasmādvapāmevāgre 'bhighārayedatha pṛṣadājyamatha yatpaśuṃ nābhighārayati nedaśṛtamabhighārayāṇītyetadevāsya sarvaḥ paśurabhighā rito bhavati yadvapāmabhighārayati tasmādvapāmevāgre 'bhighārayedatha pṛṣadājyam

But he, looking at his arms, said, 'These hoary arms--what in the world has become of the Brâhman's word!' Let him not heed that (objection of the Karakas); for this is the last fore-offering,--and this being a havis-offering, at the last fore-offering he first pours ghee into the dhruvâ, being about to offer the first two butter-portions with it. Now, on the present occasion, he will first offer the omentum; therefore let him first baste the omentum, then the clotted ghee. And though he does not baste the victim with ghee, 'lest he should baste the uncooked,' that whole victim of his yet becomes (as it were) basted with ghee in that he bastes the omentum; let him therefore first baste the omentum, then the clotted ghee.