Śatapatha Brāhmaṇa ("of a hundred paths") 1.4.1.9

1.4.1.9

so 'nvāha | pra vo vājā abhidyava iti tannu preti bhavati vājā ityannaṃ vai vājā annamevaitadabhyanūktamabhidyava ityardhamāsā vā abhidyavo 'rdhamāsānevaitadabhyanūktaṃ haviṣmanta iti paśavo vai haviṣmantaḥ paśūnevaitadabhyanūktam

He recites (the first kindling verse), 'Forth go your viands, heavenward!' this, then, tends in a forward direction. 'Viands' (vâga) he says, because viands mean food: hence food is obtained (for the sacrificer) by this recitation. 'Heavenward' he says, because those that tend heavenward are the half-moons: it is, therefore, the half-moons which he obtains by this recitation. 'In havis rich' he further says, because those that are rich in havis (milk, butter) are the cattle; it is cattle, therefore, that he thereby obtains through the recitation.