Jaiminīya (Talavakāra) Brāhmaṇa 25.147

25.147

avānnādyaṃ runddhe'nnāda śreṣṭha svānāṃ bhavati ya evaṃ veda
atha sauparṇaṃ yajñasyaivārambhaḥ
yajño vai devebhya udakrāmat
sa suparṇo bhūtaḥ paryaplavata
te devā akāmayantā yajñaṃ rabhemahīti
ta etatsāmāpaśyan
tenāstuvata
tena yajñamārabhanta
utkrānta ivaitarhi yajño bhavati ṣaṣṭhe'han
tadyadatra sauparṇaṃ bhavati yajñasyaivārambhāya
yadvevainametena suparṇaṃ bhūtaṃ pariplavamānamārabhante
tasmātsauparṇamityākhyāyate
tadvevācakṣate krauñcamiti
kruṃṅāṅrirasa īṣyamivāharavindat
īṣyamivaitadaharyatṣaṣṭham
tasmātṣaṣṭhe'hankriyate
tadaiḷe bhavati paśavo vā iḷā
paśava etadahaḥ paśūnāmevāvaruddhyai

He obtains food, he becomes an eater of food, the best among his own, who knows thus. Now the Sauparṇa: it is the grasping of the sacrifice. The sacrifice indeed departed from the gods. Having become an eagle, it flew about. Those gods desired: 'May we grasp the sacrifice.' They saw this sāman. With it they praised. With it they grasped the sacrifice. The sacrifice is departed, as it were, now on the sixth day. In that the Sauparṇa is here, it is indeed for grasping the sacrifice. And because they grasp it with this while it flies about having become an eagle, therefore it is called Sauparṇa. They also call it the Krauñca. Kruṅ Āṅgirasa found the day like a plow-pole (īṣyā). This day which is the sixth is like a plow-pole. Therefore it is performed on the sixth day. It is [composed] on iḷā; cattle indeed are iḷā. Cattle are this day; it is indeed for the obtainment of cattle.