Śatapatha Brāhmaṇa ("of a hundred paths") 9.1.2.30

9.1.2.30

abhyātmam pakṣapucāni vikarṣati | abhyātmameva tacāntiṃ dhatte purastādarvākparastādeva tadarvācīṃ śāntiṃ dhatte 'gne pāvaka rociṣeti dakṣiṇam pakṣaṃ sa naḥ pāvaka dīdiva iti pucam pāvakayā yaścitayantyā kṛpetyuttaram pāvakam pāvakamiti yadvai śivaṃ śāntaṃ tatpāvakaṃ śamayatyevainametat

Over the wings and tail he draws them in the direction of the body (self): he thus lays calmness into his own self;--from the further end (he draws) hitherwards: he thus lays calmness into his own self from the further end hitherwards. The right wing, with (Vâg. S. XVII, 8), 'O bright Agni, with thy light, (with thy dainty tongue, O god, bring hither the gods, and worship them)!' The tail, with (Vâg. S. XVII, 9), 'O bright and shining Agni, (bring hither the gods to our sacrifice and our offering)!' The left wing, with (Vâg. S. XVII, 10), 'He who with bright and glittering light (shineth upon the earth, as the dawns with their glow, who, the ever young, speeding, as in the race, in the battle, of the steed, thirsteth not in the heat).' 'Bright,' he says each time, for whatever is kindly and propitious is bright: he thus propitiates him thereby.