Śatapatha Brāhmaṇa ("of a hundred paths") 8.2.2.5

8.2.2.5

yadveva vaiśvadevīrupadadhāti | prajāpatervisrastātsarvāḥ prajā madhyata udakrāmannetasyā adhi yonestā enametasminnātmanaḥ pratihite prāpadyanta

And, again, as to why he lays down the All-gods’ (bricks). When Pragâpati had become relaxed, all creatures went forth from the midst of him, from that birth-place of theirs. When that (central part) of his body had been restored, they entered him.