Śatapatha Brāhmaṇa ("of a hundred paths") 4.1.1.7

4.1.1.7

te prātaḥsavana eva | sarvaṃ yajñaṃ samasthāpayannetasminneva grahe yajuṣṭaḥ prathame stotre sāmataḥ prathame śastra ṛktastena saṃsthitenaivāta ūrdhvaṃ yajñenācarantsa eṣo 'pyetarhi tathaiva yajñaḥ saṃtiṣṭhata etasminneva grahe yajuṣṭaḥ prathame stotre sāmataḥ prathame śastra ṛktastena saṃsthitenaivāta ūrdhvaṃ yajñena carati

Even at the morning Soma-feast they then completely established the entire sacrifice,--at this same (upâmsu) graha by means of the Yagus; at the first chant (stotra) by means of the Sâman; and at the first recitation (sastra) by means of the Rik: with that sacrifice thus completely established they subsequently worshipped. And in like manner does this sacrifice now become completely established,--by means of the Yagus at this same graha; by means of the Sâman at the first chant; and by means of the Rik at the first recitation; and with this sacrifice thus completely established he subsequently worships.