Shatapatha Brahmana 14.1.2.15

14.1.2.15

athottarataḥ pariśritam bhavati tadabhiprayanto japanti praitu brahmaṇaspatirityeṣa vai brahmaṇaspatirya eṣa tapatyeṣa u pravargyastadetamevaitatprīṇāti tasmādāha praitu brahmaṇaspatiriti pradevyetu sūnṛteti devī hyeṣā sūnṛtācā vīraṃ naryam paṅktirādhasamityupastautyevainametanmahayatyeva devā yajñaṃ nayantu na iti sarvānevāsmā etaddevānabhigoptṝ!nkaroti

Now there is an enclosed space on the north side: whilst proceeding towards that (shed) they mutter (Vâg. S. XXXVII, 7; Rig-v. I, 40, 3), 'May Brahmanaspati go forward!'--Brahmanaspati (the lord of devotion) doubtless is he that shines yonder, and the Pravargya also is that one: it is him he thus gratifies; hence he says, 'May Brahmanaspati go forward;'--'may the goddess Gladness go forward!'--for the goddess Gladness she (Vâk) is;--'unto the hero, kindly to men and the dispenser of fivefold (offerings),'--he thereby praises and magnifies it (the Pravargya),--'unto the sacrifice may the gods lead us!'--he thereby makes all the gods its guardians.