Śatapatha Brāhmaṇa ("of a hundred paths") 8.7.2.2

8.7.2.2

yadveva lokampṛṇāmupadadhāti | kṣatraṃ vai lokampṛṇā viśa imā itarā iṣṭakāḥ kṣatraṃ tadviśyattāraṃ dadhāti tāṃ sarvāsu citiṣūpadadhāti sarvasyāṃ tadviśi kṣatramattāraṃ dadhāti

And, again, as to why he lays down a Lokamprinâ,--the Lokamprinâ, doubtless, is the nobility (or chieftaincy), and these other bricks are the peasants (or clansmen): he thus places the nobility (or chieftain), as the eater, among the peasantry. He lays it down in all the layers: he thus places the nobility, as the eater, among the whole peasantry (or in every clan).