Shatapatha Brahmana 7.5.2.42

7.5.2.42

atha yāḥ pañcottarāḥ | tāścandasyāḥ paśavo vai candāṃsyannam paśavo 'nnamu paśormāṃsamatha vā etebhyaḥ paśubhyo māṃsānyutkrāntāni bhavanti tadyaccandasyā upadadhātyeṣvevaitatpaśuṣu māṃsāni dadhātyanantarhitāḥ paśubhya upadadhātyanantarhitāni tatpaśubhyo māṃsāni dadhātyantarā apasyā bhavanti bāhyāścandasyā antarā hyāpo bāhyāni māṃsāni

And the last five are the Khandasyâh (the metres’ bricks);--the metres are cattle, and cattle is food; or rather the flesh of cattle is food, and the flesh has departed from these victims: he therefore puts flesh on those cattle when he lays down the Khandasyâh. He places them close to the victims: he thereby puts the flesh close to the (bones of the) cattle. The Apasyâh are inside, the Khandasyâh outside; for the water is inside, and the flesh outside.