Śatapatha Brāhmaṇa ("of a hundred paths") 6.3.2.8

6.3.2.8

atha rāsabham | urvantarikṣaṃ vīhi svastigavyūtirabhayāni kṛṇvanniti yathaiva yajustathā bandhuḥ pūṣṇā sayujā sahetīyaṃ vai pūṣānayā sayujā sahetyetattadenaṃ rāsabhenānvicati

Then the ass with, Traverse the wide air, thou possessed of prosperous pastures and affording safety!'--as the text, so its meaning;--'with Pûshan as thy mate;'--Pûshan, doubtless, is this earth; thus, 'together with her as thy mate:' he thus searches for him by means of the ass.