Gopalacampu 1.1.19

1.1.19

pūrvottaratayā campū-dvayī seyaṃ trayī trayī |
pṛthak pṛthag grantha-tulyā yathecchaṃ sadbhir īkṣyatām || [anuṣṭubh]

Comprising the prior and the later parts, this pair of campūs is a triad of the Vedas;
let it be examined by the virtuous at their pleasure as two distinct works. ||