Śatapatha Brāhmaṇa ("of a hundred paths") 1.7.2.20

1.7.2.20

sā ha nveva samṛddhānuvākyā | yasyai prathamātpadāddevatāmabhivyāharati so eva samṛddhā yājyā yasyā uttamātpadāddevatāyā adhi vaṣaṭkaroti vīryaṃ vai devata 'rcastadubhayata evaitadvīryeṇa parigṛhya yasyai devatāyai havirbhavati tasyai prayacati

Verily, that invitatory formula alone is auspicious, in the first word of which he utters the (name of the) deity; and that offering-formula alone is auspicious in the last word of which he pronounces the vashat upon the deity; for the (name of the) deity constitutes the vigour of the Rik (verse): hence after thus enclosing it on both sides with vigour, he offers the sacrificial food to that deity for which it is intended.