Śatapatha Brāhmaṇa ("of a hundred paths") 13.8.2.9

13.8.2.9

athainadvimuñcati kṛtvā tatkarma yasmai karmaṇa enadyuṅkte vimucyantāmusriyā ityetasmā u hi karmaṇa usriyā yujyante taddakṣiṇodasyatyudagitaraddaivaṃ caiva tatpitryam ca vyākaroti

Having performed the work for which he has put the team to that (plough), he now unfastens it: 'Let the oxen be unyoked!' he says, for it is for that work that the oxen were yoked. To the right (south) side he removes this (plough and team), to the left (side) arty other: he thus keeps the divine separate from what' belongs to the Fathers.