Śatapatha Brāhmaṇa ("of a hundred paths") 4.4.2.3

4.4.2.3

sa yatprātaḥsavane vā pracaret | mādhyandine vā savane samadaṃ ha kuryāddevebhyaśca pitṛbhyaśca tena tṛtīyasavane pracarati vaiśvadevaṃ vai tṛtīyasavanaṃ tathā hāsamadaṃ karoti nānuvākyāmanvāha sakṛduhyeva parāñcaḥ pitarastasmānnānuvākyāmanvāha

But were he to offer it at the morning feast, or at the midday feast, he would cause discord between the gods and Fathers. He offers it at the evening feast, because the evening feast belongs to the All-gods: thus he does not cause discord. He recites no invitatory prayer (but only an offering prayer), for the Fathers have passed away once for all: hence he recites no invitatory prayer.