Śatapatha Brāhmaṇa ("of a hundred paths") 8.6.2.5

8.6.2.5

yadveva candasyā upadadhāti | etadvai devā etaṃ nākaṃ svargaṃ lokamapaśyannetā stomabhāgāstasminnaviśaṃsteṣāṃ viśatām prajāpatiruttamo 'viśatsa yaḥ sa prajāpatiretāstāścandasyāḥ

And, again, as to why he lays down the Khandasyâs. The gods at that time saw that firmament, the world of heaven, to wit, those Stomabhâgâs, and entered it. Of those entering, Pragâpati entered last; and thus Pragâpati is the same as these Khandasyâs.