Śatapatha Brāhmaṇa ("of a hundred paths") 1.4.1.25

1.4.1.25

taṃ tvā samidbhiraṅgira iti | samidbhirhyetamaṅgirasa aindhatāṅgira ityaṅgirā u hyagnirghṛtena vardhayāmasīti tatsāmidhenam padaṃ samevainaṃ tenendhe vīryamevāsmindadhāti

[He recites the third sâmidhenî]: 'With samidhs thee, O Aṅgiras!'--with samidhs (kindling-sticks), indeed, the Aṅgiras kindled him. 'O Aṅgiras!' he says, for Agni is indeed Aṅgiras.--'With butter we exhilarate!' This (viz. ghritena, 'with butter') is a word which is especially suitable for the kindling of Agni: by it he kindles him, and bestows vigour on this (sacrificer).