Śatapatha Brāhmaṇa ("of a hundred paths") 1.2.1.22

1.2.1.22

athaika ājyaṃ nirvapati | yadvā ādiṣṭaṃ devatāyai havirgṛhyate yāvaddevatyaṃ tadbhavati taditareṇa yajuṣā gṛhṇāti na vā etatkasyai cana devatāyai havirgṛhṇannādiśati yadājyaṃ tasmādaniruktena yajuṣā gṛhṇāti mahīnām payo 'sīti mahya iti ha vā etāsāmeke nāma yadgavāṃ tāsāṃ vā etatpayo bhavati tasmādāha mahīnām payo 'sītyevamu hāsyaitatkhalu yajuṣaiva gṛhītam bhavati tasmādvevāha mahīnām payo 'sīti

Some one pours clarified butter (into the âgyasthâlî, or butter-pot). Now whatever oblation, in being taken, is announced to a (particular) deity, that belongs to the respective deity, that he takes with a special prayer; but in taking this oblation, to wit, the butter, he does not announce it to any particular deity, and therefore takes it with an undefined formula, viz. with (Vâg. S. I, 20): 'Juice of the great ones art thou!' For 'the great ones' some (take to be) a name for the cows; and their juice indeed it is: for this reason he says, 'The juice of the great ones art thou!' And thus, moreover, is some of that (butter) taken with a sacrificial formula: and for this reason also he says, 'The juice of the great ones art thou!'