Shatapatha Brahmana 4.5.6.1

4.5.6.1

eṣa vai prajāpatiḥ | ya eṣa yajñastāyate yasmādimāḥ prajāḥ prajātā etamvevāpyetarhyanu prajāyante sa āśvinaṃ grahaṃ gṛhītvāvakāśānavakāśayati

Pragâpati, forsooth, is that sacrifice which is here performed, and whence these creatures have been produced, and in like manner are they produced therefrom even to this day. Having drawn the Asvina graha, he makes (the sacrificer) eye (the several cups, while muttering) the Avakâsa formulas.