Śatapatha Brāhmaṇa ("of a hundred paths") 2.3.4.3

2.3.4.3

tasmai kamagnī upatiṣṭheta | agnī vai dātārau tāvevaitadyācate sāyamupatiṣṭheta sāyaṃ hi devā upātiṣṭhanta datto haivāsmā etau paṣūnya evaṃ vidvānupatiṣṭhate

For this then let him respectfully approach the two fires: the fires are givers, and thereby he supplicates them. Let him approach them in the evening, for in the evening the gods approached (Agni). And whosoever, knowing this, approaches (the two fires), to him, indeed, they grant cattle.