Matsya Purana 58.35

58.35

śākraṃ raudrañca saumyaṃ ca kūṣmāṇḍaṃ jātavedasam.
saurasūktaṃ japenmantraṃ dakṣiṇena yajurvidaḥ.. 58.34 ..

Then the knowers of the Rigveda, seated in the east, should separately mutter the formulae of Râtrisûkta, Rudrasûkta, the auspicious Pâvamânasûkta, and Puruṣasûkta; in the same way the Dvârapâlas, learned in the Yajurveda, seated in the south, should separately mutter the formulae of Indra, Rudra, Soma, Kûṣmânda, Fire (Jâtavedas), and the Sun.—33-34.