Śatapatha Brāhmaṇa ("of a hundred paths") 6.3.2.7

6.3.2.7

so 'śvamutkramayati | pratūrvannehyavakrāmannaśastīreti pāpmā vā aśastistvaramāṇa ehyavakrāmanpāpmānamityetadrudrasya gāṇapatyam mayobhūrehīti raudrā vai paśavo yā te devatā tasyai gāṇapatyam mayobhūrehītyetattadenamaśvenānvicati

He makes the horse walk on, with (Vâg. S. XI, 15), 'Forth-speeding, come treading down the curses!'--curse means evil: thus, 'running come, treading down the evil!'--'come, delighting, into Rudra's chieftainship!'--beasts belong to Rudra: thus, 'come thou, delighting, into the chieftainship of him who is thy deity!' he thus searches for him by means of the horse.