Śatapatha Brāhmaṇa ("of a hundred paths") 7.2.2.9

7.2.2.9

sa dakṣiṇārdhenāgneḥ | antareṇa pariśritaḥ prācīm prathamāṃ sītāṃ kṛṣati śunaṃ su phālā vikṛṣantu bhūmiṃ śunaṃ kīnāśā abhiyantu vāhairiti śunaṃ śunamiti yadvai samṛddhaṃ tacunaṃ samardhayatyevaināmetat

On the right (south) side of the fire-altar, he ploughs first a furrow eastwards inside the enclosing-stones, with (Vâr. S. XII, 69; Rik S. IV, 57, 8), 'Right luckily may the plough-shares plough up the ground, luckily the tillers ply with their oxen!'--'luckily--luckily,' he says, 'for what is successful that is lucky:' he thus makes it (the furrow) successful.