Śatapatha Brāhmaṇa ("of a hundred paths") 6.3.3.5

6.3.3.5

atha valmīkavapā suṣirā vyadhve nihitā bhavati | tāmanvīkṣata iyaṃ vai valmīkuvapeyamu vā ime lokā etadvā enaṃ devā eṣu lokeṣu vigrāhamaicaṃstathaivainamayametadeṣu lokeṣu vigrāhamicati

Thereupon a hollow ant-hill is laid down midways (between the lump of clay and the Âhavanîya fire). He looks along it; for the ant-hill is this earth, and this earth is these worlds. For the gods searched for him (Agni) in these worlds part by part; and in like manner does this one now search for him in these worlds part by part.