Śatapatha Brāhmaṇa ("of a hundred paths") 1.2.2.7

1.2.2.7

atha puroḍāśamadhivṛṇakti | dharmo 'sīti yajñamevaitatkaroti yathā gharmam pravṛṃjyādevam pravṛṇakti viśvāyuriti tadāyurdadhāti

Now he (the Adhvaryu) puts on (adhi-vrig) the cake, with the text (Vâg. S. I, 22): 'Heat (or a hot vessel, gharma) art thou!' whereby he makes it (a means of) sacrifice, and puts it on in the same (way as if he were putting the (pravargya) cauldron gharma) on,--'Life-sustaining (visvâyus)!' he adds, whereby he obtains life (for the sacrificer).