Śatapatha Brāhmaṇa ("of a hundred paths") 13.6.2.10

13.6.2.10

brahmaṇe brāhmaṇamālabhate brahma vai brāhmaṇo brahmeva tadbrahmaṇā samardhayati kṣatrāya rājanyaṃ kṣatram vai rājanyaḥ kṣatrameva tatkṣatreṇa samardhayati marudbhyo vaiśyamm viśo vai maruto viśameva tadviśā samardhayati tapase śūdram tapo vai śūdrastapa eva tattapasā samardhayatyevametā devatā yathārūpam paśubhiḥ samardhayati tā enaṃ samṛddhāḥ samardhayanti sarvaiḥ kāmaiḥ

For the priesthood he seizes a Brâhmana, for the Brâhmana is the priesthood: he thus joins priesthood to priesthood;--for the nobility he seizes a Râganya, for the Râganya is the nobility: he thus joins nobility to nobility;--for the Maruts (he seizes) a Vaisya, for the Maruts are the clans (peasants): he thus joins peasantry to peasantry;-- for (religious) toil (he seizes) a Sûdra, for the Sûdra is toil: he thus joins toil to toil;--according to their particular form he thus supplies these divinities with victims, and, thus supplied, they supply him with all his objects of desire.