Śatapatha Brāhmaṇa ("of a hundred paths") 6.2.1.5

6.2.1.5

sa aikṣata | ime vā agnirimānevātmānamabhisaṃskaravai yathā vā agniḥ samiddho dīpyata evameṣāṃ cakṣurdīpyate yathāgnerdhūma udayata evameṣāmūṣmodayate yathāgnirabhyahitaṃ dahatyevam bapsati yathāgnerbhasma sīdatyevameṣām purīṣaṃ sīdatīme vā agnirimānevātmānamabhisaṃskaravā iti tānnānā devatābhya ālipsata vaiśvakarmaṇam puruṣaṃ vāru ṇamaśvamaindramṛṣabhaṃ tvāṣṭramavimāgneyamajam

He considered, 'They are Agni: I will fit them unto mine own self. Even as Agni, when kindled, glares, so their eye glares; even as Agni's smoke rises upwards, so vapour rises from them; even as Agni consumes what is put in him, so they devour; even as Agni's ashes fall down, so do their faeces: they are indeed Agni; I will fit them unto mine own self.' He meant to slaughter them for different deities: the Purusha (man) for Visvakarman, the horse for Varuna, the bull for Indra, the ram for Tvashtri, the he-goat for Agni.