Shatapatha Brahmana 6.8.1.5

6.8.1.5

sa yadahaḥ prayāsyantsyāt | tadaharuttarato 'gneḥ prāgana upasthāpyāthāsmintsamidhamādadhātyetadvā enaṃ devā eṣyantam purastādannenāprīṇannetayā samidhā tathaivainamayametadeṣyantam purastādannena prīṇātyetayā samidhā

Now on any day on which he may intend to drive, he gets the chariot placed north of the fire (with the pole) to the east; and puts a kindling-stick on it (the fire); for at that time the gods first regaled him (Agni) with food, with that kindling-stick, when he was about to start: and in like manner does this one now first regale him with food, with that kindling-stick, when he is about to start.