Shatapatha Brahmana 13.4.1.14

13.4.1.14

atha pauṣṇīṃ nirvapati pūṣā vai pathīnāmadhipatiraśvāyaivaitatsvastyayanaṃ karotyatho iyaṃ vai pūṣemāmevāsmā etadgoptrīṃ karoti tasya hi nārtirasti na hvalā yamiyamadhvangopāyatīmāmevāsmā etadgoptrīṃ karoti

He then prepares a (pap) for Pûshan, for Pûshan is the overlord of roads: he thus secures successful progress to the horse. But Pûshan is also this (earth): he thus makes this (earth) its guardian, for neither injury nor failure befals him whom this (earth) guards on the way; and this (earth) he thus makes its guardian.