Śatapatha Brāhmaṇa ("of a hundred paths") 4.6.6.7

4.6.6.7

anena tvevopacaret | deva savitaretadbṛhaspate preti tatsavitāram prasavāyopadhāvati sa hi devānām prasavitā bṛhaspate preti bṛhaspatirvai devānām brahmā tadya eva devānām brahmā tasmā evaitatprāha tasmādāha bṛhaspate preti

But one may also enter upon it with, 'O divine Savitar; this, O Brihaspati, forwards!' Therewith he hastes to Savitri for his impulsion, for he is the impeller (prasavitri) of the gods; and 'O Brihaspati, forwards!' he says, because Brihaspati is the Brahman of the gods,--thus he announces it to him who is the Brahman of the gods: therefore he says, 'O Brihaspati, forwards!'